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Chesterton P, Evans W, Wright M, Lolli L, Richardson M, Atkinson G. Influence of Lumbar Mobilizations During the Nordic Hamstring Exercise on Hamstring Measures of Knee Flexor Strength, Failure Point, and Muscle Activity: A Randomized Crossover Trial. J Manipulative Physiol Ther 2020; 44:1-13. [PMID: 33248746 DOI: 10.1016/j.jmpt.2020.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 09/11/2020] [Accepted: 09/11/2020] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The aims of this study were to quantify the effects of spinal mobilization on force production, failure point, and muscle activity of the hamstrings during the Nordic hamstring exercise (NHE), and to explore individual differences in responses. METHODS In a replicated randomized crossover trial, 24 asymptomatic, recreationally active men (age [mean ± standard deviation]: 27 ± 6 years; body mass: 82 ± 17 kg; height: 181 ± 8 cm) completed 2 standardized intervention trials (L4/5 zygapophyseal mobilizations) and 2 control trials. The failure point of the NHE was determined with 3D motion capture. Peak force, knee flexor torque, and electromyography (EMG) of the biceps femoris were measured. Data analyses were undertaken to quantify mean intervention response and explore any individual response heterogeneity. RESULTS Mean (95% confidence interval) left-limb force was higher in intervention than in control trials by 18.7 (4.6-32) N. Similarly, right-limb force was higher by 22.0 (3.4-40.6) N, left peak torque by 0.14 (0.06-0.22) N • m, and right peak torque by 0.14 (0.05-0.23) N • m/kg. Downward force angle was decreased in intervention vs control trials by 4.1° (0.5°-7.6°) on the side of application. Both peak EMG activity (P = .002), and EMG at the downward force (right; P = .020) increased in the intervention condition by 16.8 (7.1-26.4) and 8.8 (1.5-16.1) mV, respectively. Mean downward acceleration angle changed by only 0.3° (-8.9° to 9.4°) in intervention vs control trials. A clear response heterogeneity was indicated only for right force (Participant × Intervention interaction: P = .044; response heterogeneity standard deviation = 34.5 [5.7-48.4] N). Individual response heterogeneity was small for all other outcomes. CONCLUSION After spinal mobilization, immediate changes in bilateral hamstring force production and peak torque occurred during the NHE. The effect on the NHE failure point was unclear. Electromyographic activity increased on the ipsilateral side. Response heterogeneity was generally similar to the random trial-to-trial variability inherent in the measurement of the outcomes.
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Affiliation(s)
- Paul Chesterton
- School of Health and Life Sciences, Teesside University, Middlesbrough, United Kingdom.
| | - Will Evans
- Faculty of Health Sciences and Wellbeing, Sunderland University, Sunderland, United Kingdom
| | - Matthew Wright
- School of Health and Life Sciences, Teesside University, Middlesbrough, United Kingdom
| | - Lorenzo Lolli
- Football Exchange, Research Institute of Sport Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Mark Richardson
- School of Health and Life Sciences, Teesside University, Middlesbrough, United Kingdom
| | - Greg Atkinson
- School of Health and Life Sciences, Teesside University, Middlesbrough, United Kingdom
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Volkmann C, Volkmann A, Müller CA. On the treatment effect heterogeneity of antidepressants in major depression: A Bayesian meta-analysis and simulation study. PLoS One 2020; 15:e0241497. [PMID: 33175895 PMCID: PMC7657525 DOI: 10.1371/journal.pone.0241497] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 10/15/2020] [Indexed: 01/25/2023] Open
Abstract
Background The average treatment effect of antidepressants in major depression was found to be about 2 points on the 17-item Hamilton Depression Rating Scale, which lies below clinical relevance. Here, we searched for evidence of a relevant treatment effect heterogeneity that could justify the usage of antidepressants despite their low average treatment effect. Methods Bayesian meta-analysis of 169 randomized, controlled trials including 58,687 patients. We considered the effect sizes log variability ratio (lnVR) and log coefficient of variation ratio (lnCVR) to analyze the difference in variability of active and placebo response. We used Bayesian random-effects meta-analyses (REMA) for lnVR and lnCVR and fitted a random-effects meta-regression (REMR) model to estimate the treatment effect variability between antidepressants and placebo. Results The variability ratio was found to be very close to 1 in the best fitting models (REMR: 95% highest density interval (HDI) [0.98, 1.02], REMA: 95% HDI [1.00, 1.02]). The between-study standard deviation τ under the REMA with respect to lnVR was found to be low (95% HDI [0.00, 0.02]). Simulations showed that a large treatment effect heterogeneity is only compatible with the data if a strong correlation between placebo response and individual treatment effect is assumed. Conclusions The published data from RCTs on antidepressants for the treatment of major depression is compatible with a near-constant treatment effect. Although it is impossible to rule out a substantial treatment effect heterogeneity, its existence seems rather unlikely. Since the average treatment effect of antidepressants falls short of clinical relevance, the current prescribing practice should be re-evaluated.
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Affiliation(s)
- Constantin Volkmann
- Department of Psychiatry and Psychotherapy, Charité—Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
- * E-mail:
| | | | - Christian A. Müller
- Department of Psychiatry and Psychotherapy, Charité—Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
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Smith SM, Dworkin RH, Turk DC, McDermott MP, Eccleston C, Farrar JT, Rowbotham MC, Bhagwagar Z, Burke LB, Cowan P, Ellenberg SS, Evans SR, Freeman RL, Garrison LP, Iyengar S, Jadad A, Jensen MP, Junor R, Kamp C, Katz NP, Kesslak JP, Kopecky EA, Lissin D, Markman JD, Mease PJ, O'Connor AB, Patel KV, Raja SN, Sampaio C, Schoenfeld D, Singh J, Steigerwald I, Strand V, Tive LA, Tobias J, Wasan AD, Wilson HD. Interpretation of chronic pain clinical trial outcomes: IMMPACT recommended considerations. Pain 2020; 161:2446-2461. [PMID: 32520773 PMCID: PMC7572524 DOI: 10.1097/j.pain.0000000000001952] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Interpreting randomized clinical trials (RCTs) is crucial to making decisions regarding the use of analgesic treatments in clinical practice. In this article, we report on an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus meeting organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks, the purpose of which was to recommend approaches that facilitate interpretation of analgesic RCTs. We review issues to consider when drawing conclusions from RCTs, as well as common methods for reporting RCT results and the limitations of each method. These issues include the type of trial, study design, statistical analysis methods, magnitude of the estimated beneficial and harmful effects and associated precision, availability of alternative treatments and their benefit-risk profile, clinical importance of the change from baseline both within and between groups, presentation of the outcome data, and the limitations of the approaches used.
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Affiliation(s)
- Shannon M Smith
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, United States
- Department of Obstetrics and Gynecology, University of Rochester Medical Center, Rochester, NY, United States
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, United States
| | - Robert H Dworkin
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, United States
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY, United States
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
- Center for Health and Technology, University of Rochester Medical Center, Rochester, NY, United States
| | - Dennis C Turk
- Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, United States
| | - Michael P McDermott
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, United States
- Center for Health and Technology, University of Rochester Medical Center, Rochester, NY, United States
- Department of Biostatistics and Computational Biology, University of Rochester Medical Center, Rochester, NY, United States
| | | | - John T Farrar
- Departments of Epidemiology, Neurology, and Anesthesia, University of Pennsylvania, Philadelphia, PA, United States
- Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA, United States
| | | | - Zubin Bhagwagar
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, United States
- Rallybio, New Haven, CT, United States
| | - Laurie B Burke
- School of Pharmacy, University of Maryland, Baltimore, MD, United States
- LORA Group, LLC, Royal Oak, MD, United States
| | - Penney Cowan
- American Chronic Pain Association, Rocklin, CA, United States
| | - Susan S Ellenberg
- Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA, United States
| | - Scott R Evans
- Department of Epidemiology and Biostatistics, The George Washington University, Washington, DC, United States
| | - Roy L Freeman
- Department of Neurology, Harvard Medical School, Boston, MA, United States
| | - Louis P Garrison
- Department of Pharmacy, University of Washington, Seattle, WA, United States
| | | | - Alejandro Jadad
- Department of Anesthesia, Faculty of Medicine, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Mark P Jensen
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, United States
| | | | - Cornelia Kamp
- Center for Health and Technology, University of Rochester Medical Center, Rochester, NY, United States
- Clinical Materials Services Unit, University of Rochester Medical Center, Rochester, NY, United States
| | - Nathaniel P Katz
- Tufts University School of Medicine, Boston, MA, United States
- Analgesic Solutions, Natick, MA, United States
| | | | | | - Dmitri Lissin
- Scilex Pharmaceuticals, Palo Alto, CA, United States
| | - John D Markman
- Neuromedicine Pain Management and Translational Pain Research, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States
| | - Philip J Mease
- Rheumatology Clinical Research, Swedish Medical Center, Seattle, WA, United States
- University of Washington School of Medicine, Seattle, WA, United States
| | - Alec B O'Connor
- Department of Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Kushang V Patel
- Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, United States
| | - Srinivasa N Raja
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Cristina Sampaio
- Faculdade Medicinda de Lisboa, Universidade de Lisboa, Lisboa, Portugal
- CHDI Foundation, Princeton, NJ, United States
| | - David Schoenfeld
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, United States
| | - Jasvinder Singh
- Departments of Medicine and Epidemiology, University of Alabama at Birmingham School of Medicine, Birmingham, AB, United States
| | | | - Vibeke Strand
- Division of Immunology/Rheumatology, Stanford University, Palo Alto, CA, United States
| | | | - Jeffrey Tobias
- Aquila Consulting Group, LLC, Petaluma, CA, United States
| | - Ajay D Wasan
- Departments of Anesthesiology and Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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Hartman H, Tamura RN, Schipper MJ, Kidwell KM. Design and analysis considerations for utilizing a mapping function in a small sample, sequential, multiple assignment, randomized trials with continuous outcomes. Stat Med 2020; 40:312-326. [PMID: 33111381 DOI: 10.1002/sim.8776] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 08/11/2020] [Accepted: 09/29/2020] [Indexed: 12/19/2022]
Abstract
Small sample, sequential, multiple assignment, randomized trials (snSMARTs) are multistage trials with the overall goal of determining the best treatment after a fixed amount of time. In snSMART trials, patients are first randomized to one of three treatments and a binary (e.g. response/nonresponse) outcome is measured at the end of the first stage. Responders to first stage treatment continue their treatment. Nonresponders to first stage treatment are rerandomized to one of the remaining treatments. The same binary outcome is measured at the end of the first and second stages, and data from both stages are pooled together to find the best first stage treatment. However, in many settings the primary endpoint may be continuous, and dichotomizing this continuous variable may reduce statistical efficiency. In this article, we extend the snSMART design and methods to allow for continuous outcomes. Instead of requiring a binary outcome at the first stage for rerandomization, the probability of staying on the same treatment or switching treatment is a function of the first stage outcome. Rerandomization based on a mapping function of a continuous outcome allows for snSMART designs without requiring a binary outcome. We perform simulation studies to compare the proposed design with continuous outcomes to standard snSMART designs with binary outcomes. The proposed design results in more efficient treatment effect estimates and similar outcomes for trial patients.
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Affiliation(s)
- Holly Hartman
- Department of Biostatistics, University of Michigan, Ann Arbor, Michigan, USA
| | - Roy N Tamura
- Health Informatics Institute, University of South Florida, Tampa, Florida, USA
| | - Matthew J Schipper
- Department of Biostatistics, University of Michigan, Ann Arbor, Michigan, USA.,Department of Radiation Oncology, University of Michigan
| | - Kelley M Kidwell
- Department of Biostatistics, University of Michigan, Ann Arbor, Michigan, USA
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55
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Plow M, Motl RW, Finlayson M, Bethoux F. Response heterogeneity in a randomized controlled trial of telerehabilitation interventions among adults with multiple sclerosis. J Telemed Telecare 2020; 28:642-652. [PMID: 33100184 DOI: 10.1177/1357633x20964693] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Telerehabilitation may be effective on average but is not equally effective among all people with multiple sclerosis (MS). Thus, the purpose of this secondary analysis of a randomized controlled trial was to explore whether baseline characteristics of participants with MS influence fatigue and physical activity outcomes of three telerehabilitation interventions. METHODS Participants were randomized to contact-control intervention (CC), physical activity-only intervention (PA-only), and physical activity plus fatigue self-management intervention (FM+). The 12-week interventions were delivered over the phone. Sociodemographic (age and income), clinical (comorbidities, mental function and physical function), psychosocial (self-efficacy, outcome expectations and goal-setting), and behavioural baseline characteristics (step count and fatigue self-management behaviors) were used in a moderated regression analysis and a responder analysis to examine their influence on the Fatigue Impact Scale (FIS) and Godin Leisure-Time Exercise Questionnaire (GLTEQ) at post-test (i.e. immediately post-interventions). RESULTS No interactions terms were statistically significant in the moderation analysis. However, the responder analysis showed that baseline psychosocial characteristics and mental function were significantly different (p < 0.05) between responders and non-responders. Specifically, non-responders on the FIS at post-test in the PA-only intervention had significantly lower baseline scores in goal setting for engaging in fatigue self-management behaviours. Also, non-responders on the GLTEQ at post-test in the FM+ intervention had significantly worse baseline scores in mental function. DISCUSSION Further research is needed to understand the complex relationship among baseline characteristics, telerehabilitation and response heterogeneity. We discuss how research on examining response heterogeneity may be advanced by conducting mega-clinical trials, secondary analyses of big data, meta-analyses and employing non-traditional research designs. TRIAL REGISTRATION Clinicaltrials.gov (NCT01572714).
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Affiliation(s)
- Matthew Plow
- Frances Payne Bolton School of Nursing, Case Western Reserve University, USA
| | - Robert W Motl
- Department of Physical Therapy, The University of Alabama at Birmingham, USA
| | | | - Francois Bethoux
- Mellen Center for Multiple Sclerosis Treatment and Research, Department of Physical Medicine & Rehabilitation, Neurological Institute, The Cleveland Clinic Foundation, USA
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56
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Dennis JM. Precision Medicine in Type 2 Diabetes: Using Individualized Prediction Models to Optimize Selection of Treatment. Diabetes 2020; 69:2075-2085. [PMID: 32843566 PMCID: PMC7506836 DOI: 10.2337/dbi20-0002] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 05/07/2020] [Indexed: 12/30/2022]
Abstract
Despite the known heterogeneity of type 2 diabetes and variable response to glucose lowering medications, current evidence on optimal treatment is predominantly based on average effects in clinical trials rather than individual-level characteristics. A precision medicine approach based on treatment response would aim to improve on this by identifying predictors of differential drug response for people based on their characteristics and then using this information to select optimal treatment. Recent research has demonstrated robust and clinically relevant differential drug response with all noninsulin treatments after metformin (sulfonylureas, thiazolidinediones, dipeptidyl peptidase 4 [DPP-4] inhibitors, glucagon-like peptide 1 [GLP-1] receptor agonists, and sodium-glucose cotransporter 2 [SGLT2] inhibitors) using routinely available clinical features. This Perspective reviews this current evidence and discusses how differences in drug response could inform selection of optimal type 2 diabetes treatment in the near future. It presents a novel framework for developing and testing precision medicine-based strategies to optimize treatment, harnessing existing routine clinical and trial data sources. This framework was recently applied to demonstrate that "subtype" approaches, in which people are classified into subgroups based on features reflecting underlying pathophysiology, are likely to have less clinical utility compared with approaches that combine the same features as continuous measures in probabilistic "individualized prediction" models.
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Affiliation(s)
- John M Dennis
- Institute of Biomedical and Clinical Science, Royal Devon and Exeter Hospital, University of Exeter Medical School, Exeter, U.K.
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57
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Wilkinson J, Arnold KF, Murray EJ, van Smeden M, Carr K, Sippy R, de Kamps M, Beam A, Konigorski S, Lippert C, Gilthorpe MS, Tennant PWG. Time to reality check the promises of machine learning-powered precision medicine. LANCET DIGITAL HEALTH 2020; 2:e677-e680. [PMID: 33328030 PMCID: PMC9060421 DOI: 10.1016/s2589-7500(20)30200-4] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/29/2020] [Accepted: 08/07/2020] [Indexed: 12/14/2022]
Abstract
Machine learning methods, combined with large electronic health
databases, could enable a personalised approach to medicine through improved
diagnosis and prediction of individual responses to therapies. If successful,
this strategy would represent a revolution in clinical research and practice.
However, although the vision of individually tailored medicine is alluring,
there is a need to distinguish genuine potential from hype. We argue that the
goal of personalised medical care faces serious challenges, many of which cannot
be addressed through algorithmic complexity, and call for collaboration between
traditional methodologists and experts in medical machine learning to avoid
extensive research waste.
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Affiliation(s)
- Jack Wilkinson
- Centre for Biostatistics, Manchester Academic Health Science Centre, Division of Population Health, Health Services Research and Primary Care, University of Manchester, Manchester, UK.
| | - Kellyn F Arnold
- Leeds Institute for Data Analytics, University of Leeds, Leeds, UK; Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Eleanor J Murray
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - Maarten van Smeden
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, Netherlands
| | - Kareem Carr
- Department of Biostatistics, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Rachel Sippy
- Institute for Global Health and Translational Science, SUNY Upstate Medical University, Syracuse, NY, USA; Department of Geography, University of Florida, Gainesville, FL, USA; Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Marc de Kamps
- Leeds Institute for Data Analytics, University of Leeds, Leeds, UK; School of Computing, University of Leeds, Leeds, UK
| | - Andrew Beam
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - Stefan Konigorski
- Digital Health & Machine Learning Research Group, Hasso Plattner Institut for Digital Engineering, Potsdam, Germany; Hasso Plattner Institute for Digital Health at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Christoph Lippert
- Digital Health & Machine Learning Research Group, Hasso Plattner Institut for Digital Engineering, Potsdam, Germany; Hasso Plattner Institute for Digital Health at Mount Sinai, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Mark S Gilthorpe
- Leeds Institute for Data Analytics, University of Leeds, Leeds, UK; Faculty of Medicine and Health, University of Leeds, Leeds, UK; Alan Turing Institute, London, UK
| | - Peter W G Tennant
- Leeds Institute for Data Analytics, University of Leeds, Leeds, UK; Faculty of Medicine and Health, University of Leeds, Leeds, UK; Alan Turing Institute, London, UK
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Smith SM, Fava M, Jensen MP, Mbowe OB, McDermott MP, Turk DC, Dworkin RH. John D. Loeser Award Lecture: Size does matter, but it isn't everything: the challenge of modest treatment effects in chronic pain clinical trials. Pain 2020; 161 Suppl 1:S3-S13. [PMID: 33090735 PMCID: PMC7434212 DOI: 10.1097/j.pain.0000000000001849] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/18/2020] [Accepted: 02/20/2020] [Indexed: 01/24/2023]
Affiliation(s)
- Shannon M. Smith
- Departments of Anesthesiology and Perioperative Medicine
- Obstetrics and Gynecology and
- Psychiatry, University of Rochester, Rochester, NY, United States
| | - Maurizio Fava
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, United States
| | - Mark P. Jensen
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA, United States
| | - Omar B. Mbowe
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, United States
| | - Michael P. McDermott
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester, NY, United States
- Department of Neurology, University of Rochester, Rochester, NY, United States
- Center for Health + Technology, University of Rochester, Rochester, NY, United States
| | - Dennis C. Turk
- Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, United States
| | - Robert H. Dworkin
- Departments of Anesthesiology and Perioperative Medicine
- Psychiatry, University of Rochester, Rochester, NY, United States
- Department of Neurology, University of Rochester, Rochester, NY, United States
- Center for Health + Technology, University of Rochester, Rochester, NY, United States
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Munkholm K, Winkelbeiner S, Homan P. Individual response to antidepressants for depression in adults-a meta-analysis and simulation study. PLoS One 2020; 15:e0237950. [PMID: 32853222 PMCID: PMC7451660 DOI: 10.1371/journal.pone.0237950] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 08/05/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The observation that some patients appear to respond better to antidepressants for depression than others encourages the assumption that the effect of antidepressants differs between individuals and that treatment can be personalized. OBJECTIVE To compare the outcome variance in patients receiving antidepressants with the outcome variance in patients receiving placebo in randomized controlled trials (RCTs) of adults with major depressive disorder (MDD) and to illustrate, using simulated data, components of variation of RCTs. METHODS From a dataset comprising 522 RCTs of antidepressants for adult MDD, we selected the placebo-controlled RCTs reporting outcomes on the 17 or 21 item Hamilton Depression Rating Scale or the Montgomery-Asberg Depression Rating Scale and extracted the means and SDs of raw endpoint scores or baseline to endpoint changes scores on eligible depression symptom rating scales. We conducted inverse variance random-effects meta-analysis with the variability ratio (VR), the ratio between the outcome variance in the group of patients receiving antidepressants and the outcome variance in the group receiving placebo, as the primary outcome. An increased variance in the antidepressant group would indicate individual differences in response to antidepressants. RESULTS We analysed 222 RCTs that investigated 19 different antidepressants compared with placebo in 345 comparisons, comprising a total of 61144 adults with an MDD diagnosis. Across all comparisons, the VR for raw endpoint scores was 0.98 (95% CI 0.96 to 1.00, I2 = 0%) and 1.00 (95% CI 0.99 to 1.02, I2 = 0%) for baseline-to-endpoint change scores. CONCLUSION Based on these data, we cannot reject the null hypothesis of equal variances in the antidepressant group and the placebo group. Given that RCTs cannot provide direct evidence for individual treatment effects, it may be most reasonable to assume that the average effect of antidepressants applies also to the individual patient.
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Affiliation(s)
- Klaus Munkholm
- Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark
| | | | - Philipp Homan
- Psychiatric University Hospital Zurich, University of Zurich, Zurich, Switzerland
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Sainani KL, Borg DN, Caldwell AR, Butson ML, Tenan MS, Vickers AJ, Vigotsky AD, Warmenhoven J, Nguyen R, Lohse KR, Knight EJ, Bargary N. Call to increase statistical collaboration in sports science, sport and exercise medicine and sports physiotherapy. Br J Sports Med 2020; 55:118-122. [PMID: 32816788 PMCID: PMC7788220 DOI: 10.1136/bjsports-2020-102607] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2020] [Indexed: 12/21/2022]
Affiliation(s)
- Kristin L Sainani
- Epidemiology and Population Health, Stanford University, Stanford, California, USA
| | - David N Borg
- Menzies Health Institute Queensland, Griffith University, Nathan, Queensland, Australia
| | - Aaron R Caldwell
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA
| | - Michael L Butson
- Deptartment of Health & Medical Sciences, Swinburne University of Technology, Hawthorn, Victoria, Australia
| | - Matthew S Tenan
- Optimum Performance Analytics Associates LLC, Apex, North Carolina, USA
| | - Andrew J Vickers
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Andrew D Vigotsky
- Departments of Biomedical Engineering and Statistics, Northwestern University, Evanston, Illinois, USA
| | - John Warmenhoven
- Exercise & Sport Science, Faculty of Health Sciences, University of Sydney, Sydney, New South Wales, Australia.,Australian Institute of Sport, Canberra, Australian Capital Territory, Australia
| | - Robert Nguyen
- Department of Mathematics and Statistics, University of New South Wales, Sydney, New South Wales, Australia
| | - Keith R Lohse
- Health, Kinesiology, and Recreation; Department of Physical Therapy and Athletic Training, University of Utah Health, Salt Lake City, Utah, USA
| | - Emma J Knight
- School of Public Health, University of Adelaide, Adelaide, South Australia, Australia
| | - Norma Bargary
- Department of Mathematics and Statistics, University of Limerick, Limerick, Ireland
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61
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Bonafiglia JT, Brennan AM, Ross R, Gurd BJ. An appraisal of the SD IR as an estimate of true individual differences in training responsiveness in parallel-arm exercise randomized controlled trials. Physiol Rep 2020; 7:e14163. [PMID: 31325240 PMCID: PMC6642277 DOI: 10.14814/phy2.14163] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 12/27/2022] Open
Abstract
Calculating the standard deviation of individual responses (SDIR) is recommended for estimating the magnitude of individual differences in training responsiveness in parallel‐arm exercise randomized controlled trials (RCTs). The purpose of this review article is to discuss potential limitations of parallel‐arm exercise RCTs that may confound/complicate the interpretation of the SDIR. To provide context for this discussion, we define the sources of variation that contribute to variability in the observed responses to exercise training and review the assumptions that underlie the interpretation of SDIR as a reflection of true individual differences in training responsiveness. This review also contains two novel analyses: (1) we demonstrate differences in variability in changes in diet and physical activity habits across an intervention period in both exercise and control groups, and (2) we examined participant dropout data from six RCTs and found that significantly (P < 0.001) more participants in control groups (12.8%) dropped out due to dissatisfaction with group assignment compared to exercise groups (3.4%). These novel analyses raise the possibility that the magnitude of within‐subject variability may not be equal between exercise and control groups. Overall, this review highlights that potential limitations of parallel‐arm exercise RCTs can violate the underlying assumptions of the SDIR and suggests that these limitations should be considered when interpreting the SDIR as an estimate of true individual differences in training responsiveness.
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Affiliation(s)
- Jacob T Bonafiglia
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario
| | - Andrea M Brennan
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario
| | - Robert Ross
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario
| | - Brendon J Gurd
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario
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Feczko E, Fair DA. Methods and Challenges for Assessing Heterogeneity. Biol Psychiatry 2020; 88:9-17. [PMID: 32386742 PMCID: PMC8404882 DOI: 10.1016/j.biopsych.2020.02.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/30/2019] [Accepted: 02/07/2020] [Indexed: 01/14/2023]
Abstract
The widely acknowledged homogeneity assumption limits progress in refining clinical diagnosis, understanding mechanisms, and developing new treatments for mental health disorders. This homogeneity assumption drives both a comorbidity and a heterogeneity problem, where two different approaches tackle the problems. One, a unifying approach, tackles the comorbidity problem by assuming that a single general psychopathology factor underlies multiple disorders. Another, a multifactorial approach, tackles the heterogeneity problem by assuming that disorders comprise multiple subtypes driven by multiple discrete factors. We show how each of these approaches can make useful contributions to mental health-related research and clinical practice. For example, the unifying approach can develop a rapid assessment tool that may be clinically valuable for triaging cases. The multifactorial approach can reveal subtypes that are differentially responsive to treatments and highlight distinct mechanisms leading to similar phenotypes. Because both approaches tackle different problems, both have different limitations. We describe the statistical frameworks that incorporate and adjudicate between both approaches (e.g., the bifactor model, normative modeling, and the functional random forest). Such frameworks can identify whether sets of disorders are more affected by heterogeneity or comorbidity. Therefore, future studies that incorporate such frameworks can provide further insight into the nature of psychopathology.
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Affiliation(s)
- Eric Feczko
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon.
| | - Damien A Fair
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, Oregon; Advanced Imaging Research Center, Oregon Health & Science University, Portland, Oregon
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63
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Zhang X, de Leon J, Crespo-Facorro B, Diaz FJ. Measuring individual benefits of psychiatric treatment using longitudinal binary outcomes: Application to antipsychotic benefits in non-cannabis and cannabis users. J Biopharm Stat 2020; 30:916-940. [DOI: 10.1080/10543406.2020.1765371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Xuan Zhang
- Department of Biostatistics, The University of Kansas Medical Center, Kansas City, KS, United States
- Boston Strategic Partners, Inc, Boston, MA, United States
| | - Jose de Leon
- Mental Health Research Center at Eastern State Hospital, Lexington, KY, United States
| | - Benedicto Crespo-Facorro
- University Hospital Virgen Del Rocío, Seville, Spain
- CIBERSAM G26-IBiS, University of Seville, Seville, Spain
- Department of Psychiatry, Marqués De Valdecilla University Hospital, IDIVAL, Santander, Spain
- School of Medicine, University of Cantabria, Santander, Spain
| | - Francisco J. Diaz
- Department of Biostatistics, The University of Kansas Medical Center, Kansas City, KS, United States
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Maslej MM, Furukawa TA, Cipriani A, Andrews PW, Mulsant BH. Individual Differences in Response to Antidepressants: A Meta-analysis of Placebo-Controlled Randomized Clinical Trials. JAMA Psychiatry 2020; 77:607-617. [PMID: 32074273 PMCID: PMC7042922 DOI: 10.1001/jamapsychiatry.2019.4815] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
IMPORTANCE Antidepressants are commonly used worldwide to treat major depressive disorder. Symptomatic response to antidepressants can vary depending on differences between individuals; however, this variability may reflect nonspecific or random factors. OBJECTIVES To investigate the assumption of systematic variability in symptomatic response to antidepressants and to assess whether this variability is associated with severity of major depressive disorder, antidepressant class, or year of study publication. DATA SOURCES Data used were from a recent network meta-analysis of acute treatment with licensed antidepressants in adults with major depressive disorder. The following databases were searched from inception to January 8, 2016: the Cochrane Central Register of Controlled Trials, CINAHL, Embase, LILACS database, MEDLINE, MEDLINE In-Process, and PsycINFO. Additional sources were international trial registries, drug approval agency websites, and key scientific journals. STUDY SELECTION Analysis was restricted to double-blind, randomized placebo-controlled trials with available data at the study's end point. DATA EXTRACTION AND SYNTHESIS Baseline and end point means, SDs, number of participants in each group, antidepressant class, and publication year were extracted. The data were analyzed between August 14 and November 18, 2019. MAIN OUTCOMES AND MEASURES With the use of validated methods, coefficients of variation were derived for antidepressants and placebo, and their ratios were calculated to compare outcome variability between antidepressant and placebo. Ratios were entered into a random-effects model, with the expectation that response to antidepressants would be more variable than response to placebo. Analysis was repeated after stratifying by baseline severity of depression, antidepressant class (selective serotonin reuptake inhibitors: citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline, and vilazodone; serotonin and norepinephrine reuptake inhibitors: desvenlafaxine and venlafaxine; norepinephrine-dopamine reuptake inhibitor: bupropion; noradrenergic agents: amitriptyline and reboxetine; and other antidepressants: agomelatine, mirtazapine, and trazodone), and publication year. RESULTS In the 87 eligible randomized placebo-controlled trials (17 540 unique participants), there was significantly more variability in response to antidepressants than to placebo (coefficients of variation ratio, 1.14; 95% CI, 1.11-1.17; P < .001). Baseline severity of depression did not moderate variability in response to antidepressants. Variability in response to selective serotonin reuptake inhibitors was lower than variability in response to noradrenergic agents (coefficients of variation ratio, 0.88; 95% CI, 0.80-0.97; P = .01), as was the variability in response to other antidepressants compared with noradrenergic agents (coefficients of variation ratio, 0.87; 95% CI, 0.79-0.97; P = .001). Variability also tended to be lower in studies that were published more recently, with coefficients of variation changing by a value of 0.005 (95% CI, 0.002-0.008; P = .003) for every year a study is more recent. CONCLUSIONS AND RELEVANCE Individual differences may be systematically associated with responses to antidepressants in major depressive disorder beyond placebo effects or statistical factors. This study provides empirical support for identifying moderators and personalizing antidepressant treatment.
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Affiliation(s)
- Marta M. Maslej
- Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
| | - Toshiaki A. Furukawa
- Department of Health Promotion and Human Behavior, Kyoto University Graduate School of Medicine, School of Public Health, Yoshida-Konoe, Sakyo, Kyoto, Japan,Department of Clinical Epidemiology, Kyoto University Graduate School of Medicine, Kyoto University School of Public Health, Yoshida-Konoe, Sakyo, Kyoto, Japan
| | - Andrea Cipriani
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom,Warneford Hospital, Oxford Health National Health Service Foundation Trust, Oxford, United Kingdom
| | - Paul W. Andrews
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Benoit H. Mulsant
- Centre for Addiction and Mental Health, Toronto, Ontario, Canada,Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada
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Blagrove RC, Bruinvels G, Pedlar CR. Variations in strength-related measures during the menstrual cycle in eumenorrheic women: A systematic review and meta-analysis. J Sci Med Sport 2020; 23:1220-1227. [PMID: 32456980 DOI: 10.1016/j.jsams.2020.04.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 03/10/2020] [Accepted: 04/30/2020] [Indexed: 01/06/2023]
Abstract
OBJECTIVES To systematically review the current body of research that has investigated changes in strength-related variables during different phases of the menstrual cycle in eumenorrheic women. DESIGN Systematic review and meta-analysis. METHODS A literature search was conducted in Pubmed, SPORTDiscus and Web of Science using search terms related to the menstrual cycle and strength-related measures. Two reviewers reached consensus that 21 studies met the criteria for inclusion. Methodological rigour was assessed using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Random effects meta-analyses were used to compare the early-follicular, ovulatory and mid-luteal phases for maximal voluntary contraction, isokinetic peak torque, and explosive strength. RESULTS The assessment of study quality showed that a high level of bias exists in specific areas of study design. Non-significant and small or trivial effect sizes (p≥0.26, Hedges g≤0.35) were identified for all strength-related variables in each comparison between phases. 95% confidence intervals for each comparison suggested the uncertainty associated with each estimate extends to a small effect on strength performance with unclear direction (-0.42≤g≤0.48). The heterogeneity for each comparison was also small (p≥0.83, I2=0%). CONCLUSIONS Strength-related measures appear to be minimally altered (g≤0.35) by the fluctuations in ovarian sex hormones that occur during the menstrual cycle. This finding should be interpreted with caution due to the methodological shortcomings identified by the quality assessment.
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Affiliation(s)
- Richard C Blagrove
- School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, United Kingdom.
| | - Georgie Bruinvels
- School of Sport, Health and Applied Science, St Mary's University, Twickenham, United Kingdom; Orreco Ltd, National University of Ireland Business Innovation Centre, Galway, Ireland
| | - Charles R Pedlar
- School of Sport, Health and Applied Science, St Mary's University, Twickenham, United Kingdom; Orreco Ltd, National University of Ireland Business Innovation Centre, Galway, Ireland; Division of Surgery and Interventional Science, University College London, London, United Kingdom
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66
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Riley RD, Debray TPA, Fisher D, Hattle M, Marlin N, Hoogland J, Gueyffier F, Staessen JA, Wang J, Moons KGM, Reitsma JB, Ensor J. Individual participant data meta-analysis to examine interactions between treatment effect and participant-level covariates: Statistical recommendations for conduct and planning. Stat Med 2020; 39:2115-2137. [PMID: 32350891 PMCID: PMC7401032 DOI: 10.1002/sim.8516] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 02/07/2020] [Accepted: 02/08/2020] [Indexed: 01/06/2023]
Abstract
Precision medicine research often searches for treatment‐covariate interactions, which refers to when a treatment effect (eg, measured as a mean difference, odds ratio, hazard ratio) changes across values of a participant‐level covariate (eg, age, gender, biomarker). Single trials do not usually have sufficient power to detect genuine treatment‐covariate interactions, which motivate the sharing of individual participant data (IPD) from multiple trials for meta‐analysis. Here, we provide statistical recommendations for conducting and planning an IPD meta‐analysis of randomized trials to examine treatment‐covariate interactions. For conduct, two‐stage and one‐stage statistical models are described, and we recommend: (i) interactions should be estimated directly, and not by calculating differences in meta‐analysis results for subgroups; (ii) interaction estimates should be based solely on within‐study information; (iii) continuous covariates and outcomes should be analyzed on their continuous scale; (iv) nonlinear relationships should be examined for continuous covariates, using a multivariate meta‐analysis of the trend (eg, using restricted cubic spline functions); and (v) translation of interactions into clinical practice is nontrivial, requiring individualized treatment effect prediction. For planning, we describe first why the decision to initiate an IPD meta‐analysis project should not be based on between‐study heterogeneity in the overall treatment effect; and second, how to calculate the power of a potential IPD meta‐analysis project in advance of IPD collection, conditional on characteristics (eg, number of participants, standard deviation of covariates) of the trials (potentially) promising their IPD. Real IPD meta‐analysis projects are used for illustration throughout.
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Affiliation(s)
- Richard D Riley
- Centre for Prognosis Research, School of Primary, Community and Social Care, Keele University, Staffordshire, UK
| | - Thomas P A Debray
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - David Fisher
- MRC Clinical Trials Unit, Institute of Clinical Trials & Methodology, Faculty of Population Health Sciences, University College London, London, UK
| | - Miriam Hattle
- Centre for Prognosis Research, School of Primary, Community and Social Care, Keele University, Staffordshire, UK
| | - Nadine Marlin
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Jeroen Hoogland
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Jan A Staessen
- Department of Cardiovascular Sciences, Research Unit Hypertension and Cardiovascular Epidemiology, Studies Coordinating Centre, KU Leuven, Leuven, Belgium
| | - Jiguang Wang
- Centre for Epidemiological Studies and Clinical Trials, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Karel G M Moons
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Johannes B Reitsma
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Joie Ensor
- Centre for Prognosis Research, School of Primary, Community and Social Care, Keele University, Staffordshire, UK
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67
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Population enrichment for critical care trials: phenotypes and differential outcomes. Curr Opin Crit Care 2020; 25:489-497. [PMID: 31335383 DOI: 10.1097/mcc.0000000000000641] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Sepsis and acute respiratory distress syndrome (ARDS) are two heterogenous acute illnesses where numerous RCTs have indeterminate results. We present a narrative review on the recent developments in enriching patient populations for future sepsis and ARDS trials. RECENT FINDINGS Many researchers are actively pursuing enrichment strategies to reduce heterogeneity to increase the sensitivity of future trials. Enrichment refers to the use of measurable patient characteristics, known before randomisation, to refine trial populations. Biomarkers could increase the diagnostic certainty of sepsis, whereas chest radiology training to enhance reliability of interpretation and stabilisation period of mechanical ventilation have been considered to increase the diagnostic certainty of ARDS. Clinical and biomarker data analyses identifies four to six sepsis clinical phenotypes and two ARDS clinical phenotypes. Similarly, leukocyte gene expression data identifies two to four sepsis molecular phenotypes. Use of a test-dose identifies ARDS subpopulations who are likely to benefit from higher PEEP. Early-phase trials report how a biomarker that is altered by the intervention, such as lymphocyte count for recombinant interleukin-7 therapy and higher check point inhibitor expression for anti-check point treatments in sepsis, could identify a higher treatment effect population for future trials. SUMMARY Enrichment reduces heterogeneity and will enhance the sensitivity of future trials. However, enrichment, even when it identifies more homogenous populations, may not be efficient to deploy in trials or clinical practice.
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68
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Affiliation(s)
- Sunjae Bae
- Department of Epidemiology, Johns Hopkins School of Public Health, Baltimore, Maryland.,Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Biostatistics, Johns Hopkins School of Public Health, Baltimore, Maryland
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69
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Benda N, Haenisch B. Enrichment designs using placebo nonresponders. Pharm Stat 2020; 19:303-314. [PMID: 31899854 DOI: 10.1002/pst.1992] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 10/29/2019] [Accepted: 11/04/2019] [Indexed: 11/06/2022]
Abstract
Enrichment designs that select placebo nonresponders have gained much attention during the last years in areas with high placebo response rates, eg, in depression. Proposals were made that re-randomize patients who did not respond to placebo during a first study phase as the sequential parallel design (SPD). This design uses in a second phase an enriched patient population where the treatment effect is expected to be more pronounced. This may be problematic if an effect in the overall population is claimed. Proposals were made to combine the treatment effects in the overall population from study phase 1 and the enriched population from study phase 2, alleviating but not solving the issue of a potential selection bias. This paper shows how this bias corresponding to the effect difference between the overall population and the enriched population depends on the variability of a potential subject-by-treatment interaction. Sample sizes are given, which lead to a significant result in the combining test with a given probability if actually the average effect in the overall population is zero. If, on the other hand, no subject-by-treatment interaction is given, the enrichment is shown to be inefficient. We conclude that enrichment designs using placebo nonresponders are not able to claim a positive average effect in the overall population if a subject-by-treatment interaction cannot be excluded. It cannot be used to demonstrate positive efficacy in the overall population in a pivotal phase III trial but may be used in early phases to demonstrate varying treatment effects between patients.
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Affiliation(s)
- Norbert Benda
- Research Department, Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany.,Department of Medical Statistics, University Medical Center Göttingen, Göttingen, Germany
| | - Britta Haenisch
- Research Department, Federal Institute for Drugs and Medical Devices (BfArM), Bonn, Germany.,Population Health Sciences, German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Center for Translational Medicine, University of Bonn, Bonn, Germany
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70
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Plöderl M, Hengartner MP. What are the chances for personalised treatment with antidepressants? Detection of patient-by-treatment interaction with a variance ratio meta-analysis. BMJ Open 2019; 9:e034816. [PMID: 31874900 PMCID: PMC7008413 DOI: 10.1136/bmjopen-2019-034816] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES To investigate if the treatment effect of antidepressants in patients with depression substantially varies in each patient (patient-by-treatment interaction or treatment heterogeneity), a necessary but largely unexplored prerequisite of personalised antidepressant treatment. DESIGN Meta-analytic variance comparison of treatment outcome between drug arms and placebo arms of clinical trials, based on the assumption that patient-by-treatment interaction should lead to larger variances in drug arms than placebo arms. To put the results into context, we run simple simulations, assuming different definitions and rates of those who respond especially well to antidepressants. DATA SOURCES 163 randomised, placebo-controlled trials (51 396 patients) with complete results for pre-post differences, selected from a recently published systematic review. ANALYSIS Variance ratios (VRs) and coefficients of variance ratios (CVRs) of individual trials were meta-analytically combined. The analysis was repeated for classes of antidepressants and specific antidepressants. RESULTS VRs (VR=1.01, CI 0.99 to 1.02) and CVRs (CVR=0.82, CI 0.80 to 0.84) of the antidepressant-treatment arms were comparable or smaller than in placebo arms. Similar results were observed for classes of antidepressants and for specific antidepressants. Our simulation analysis confirmed that equal VRs can only be obtained if they are not more than a few patients who respond slightly above average. CONCLUSIONS The lack of increased treatment-outcome variance in the antidepressants versus placebo groups in randomised controlled trials indicates that no or only very small subgroups of patients respond particularly well to antidepressants. Thus, the scope for personalised treatment with antidepressants seems to be limited.
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Affiliation(s)
- Martin Plöderl
- Department of Clinical Psychology, University Clinic for Psychiatry, Psychotherapy, and Psychosomatics, Salzburg, Austria
- Department of Crisis Intervention and Suicide Prevention, Christian Doppler Clinic, Paracelsus Medical University, Salzburg, Austria
| | - Michael Pascal Hengartner
- Section for Clinical Psychology and Health Psychology, Zurich University of Applied Sciences/ZHAW, Zurich, Switzerland
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71
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Wilkinson J, Brison DR, Duffy JMN, Farquhar CM, Lensen S, Mastenbroek S, van Wely M, Vail A. Don’t abandon RCTs in IVF. We don’t even understand them. Hum Reprod 2019. [PMCID: PMC6994932 DOI: 10.1093/humrep/dez199] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The conclusion of the Human Fertilisation and Embryology Authority that ‘add-on’ therapies in IVF are not supported by high-quality evidence has prompted new questions regarding the role of the randomized controlled trial (RCT) in evaluating infertility treatments. Critics argue that trials are cumbersome tools that provide irrelevant answers. Instead, they argue that greater emphasis should be placed on large observational databases, which can be analysed using powerful algorithms to determine which treatments work and for whom. Although the validity of these arguments rests upon the sciences of statistics and epidemiology, the discussion to date has largely been conducted without reference to these fields. We aim to remedy this omission, by evaluating the arguments against RCTs in IVF from a primarily methodological perspective. We suggest that, while criticism of the status quo is warranted, a retreat from RCTs is more likely to make things worse for patients and clinicians.
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Affiliation(s)
- J Wilkinson
- Centre for Biostatistics, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - D R Brison
- Department of Reproductive Medicine, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester, UK
- Maternal and Fetal Health Research Centre, Faculty of Life Sciences, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - J M N Duffy
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK
- Balliol College, University of Oxford, Oxford, UK
| | - C M Farquhar
- Cochrane Gynecology and Fertility Group, Department of Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand
| | - S Lensen
- Cochrane Gynecology and Fertility Group, Department of Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand
| | - S Mastenbroek
- Amsterdam UMC, University of Amsterdam, Center for Reproductive Medicine, Amsterdam Reproduction & Development Research Institute, Amsterdam, Netherlands
| | - M van Wely
- Amsterdam UMC, University of Amsterdam, Center for Reproductive Medicine, Amsterdam Reproduction & Development Research Institute, Amsterdam, Netherlands
| | - A Vail
- Centre for Biostatistics, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
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Goltz FR, Thackray AE, Varela-Mato V, King JA, Dorling JL, Dowejko M, Mastana S, Thompson J, Atkinson G, Stensel DJ. Exploration of associations between the FTO rs9939609 genotype, fasting and postprandial appetite-related hormones and perceived appetite in healthy men and women. Appetite 2019; 142:104368. [PMID: 31310836 DOI: 10.1016/j.appet.2019.104368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/18/2019] [Accepted: 07/10/2019] [Indexed: 01/14/2023]
Abstract
BACKGROUND The fat mass and obesity-associated gene (FTO) rs9939609 A-allele has been associated with obesity risk. Although the exact mechanisms involved remain unknown, the FTO rs9939609 A-allele has been associated with an impaired postprandial suppression of appetite. OBJECTIVES To explore the influence of FTO rs9939609 genotype on fasting and postprandial appetite-related hormones and perceived appetite in a heterogeneous sample of men and women. DESIGN 112 healthy men and women aged 18-50-years-old completed three laboratory visits for the assessment of FTO rs9939609 genotype, body composition, aerobic fitness, resting metabolic rate, visceral adipose tissue, liver fat, fasting leptin, and fasting and postprandial acylated ghrelin, total PYY, insulin, glucose and perceived appetite. Participants wore accelerometers for seven consecutive days for the assessment of physical activity and sedentary behaviour. Multivariable general linear models quantified differences between FTO rs9939609 groups for fasting and postprandial appetite outcomes, with and without the addition of a priori selected physiological and behavioural covariates. Sex-specific univariable Pearson's correlation coefficients were quantified between the appetite-related outcomes and individual characteristics. RESULTS 95% confidence intervals for mean differences between FTO rs9939609 groups overlapped zero in unadjusted and adjusted general linear models for all fasting (P ≥ 0.28) and postprandial (P ≥ 0.19) appetite-related outcomes. Eta2 values for explained variance attributable to FTO rs9939609 were <5% for all outcomes. An exploratory correlation matrix indicated that associations between fasting and postprandial acylated ghrelin, total PYY and general or abdominal adiposity were also small (r = -0.23 to 0.15, P ≥ 0.09). Fasting leptin, glucose and insulin and postprandial insulin concentrations were associated with adiposity outcomes (r = 0.29 to 0.81, P ≤ 0.033). CONCLUSIONS Associations between the FTO rs9939609 genotype and fasting or postprandial appetite-related outcomes were weak in healthy men and women.
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Affiliation(s)
- Fernanda R Goltz
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom; University Hospitals of Leicester NHS Trust, Infirmary Square, Leicester, United Kingdom
| | - Alice E Thackray
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom; University Hospitals of Leicester NHS Trust, Infirmary Square, Leicester, United Kingdom
| | - Veronica Varela-Mato
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - James A King
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom; University Hospitals of Leicester NHS Trust, Infirmary Square, Leicester, United Kingdom
| | - James L Dorling
- Ingestive Behavior Laboratory, Pennington Biomedical Research Center, Baton Rouge, United States
| | - Monika Dowejko
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Sarabjit Mastana
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Julie Thompson
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom; University Hospitals of Leicester NHS Trust, Infirmary Square, Leicester, United Kingdom
| | - Greg Atkinson
- School of Health and Social Care, Teesside University, Middlesbrough, United Kingdom
| | - David J Stensel
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom; University Hospitals of Leicester NHS Trust, Infirmary Square, Leicester, United Kingdom.
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73
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O'Keeffe M, O'Sullivan P, Purtill H, Bargary N, O'Sullivan K. Cognitive functional therapy compared with a group-based exercise and education intervention for chronic low back pain: a multicentre randomised controlled trial (RCT). Br J Sports Med 2019; 54:782-789. [PMID: 31630089 PMCID: PMC7361017 DOI: 10.1136/bjsports-2019-100780] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2019] [Indexed: 12/29/2022]
Abstract
Background One-size-fits-all interventions reduce chronic low back pain (CLBP) a small amount. An individualised intervention called cognitive functional therapy (CFT) was superior for CLBP compared with manual therapy and exercise in one randomised controlled trial (RCT). However, systematic reviews show group interventions are as effective as one-to-one interventions for musculoskeletal pain. This RCT investigated whether a physiotherapist-delivered individualised intervention (CFT) was more effective than physiotherapist-delivered group-based exercise and education for individuals with CLBP. Methods 206 adults with CLBP were randomised to either CFT (n=106) or group-based exercise and education (n=100). The length of the CFT intervention varied according to the clinical progression of participants (mean=5 treatments). The group intervention consisted of up to 6 classes (mean=4 classes) over 6–8 weeks. Primary outcomes were disability and pain intensity in the past week at 6 months and 12months postrandomisation. Analysis was by intention-to-treat using linear mixed models. Results CFT reduced disability more than the group intervention at 6 months (mean difference, 8.65; 95% CI 3.66 to 13.64; p=0.001), and at 12 months (mean difference, 7.02; 95% CI 2.24 to 11.80; p=0.004). There were no between-group differences observed in pain intensity at 6 months (mean difference, 0.76; 95% CI -0.02 to 1.54; p=0.056) or 12 months (mean difference, 0.65; 95% CI -0.20 to 1.50; p=0.134). Conclusion CFT reduced disability, but not pain, at 6 and 12 months compared with the group-based exercise and education intervention. Future research should examine whether the greater reduction in disability achieved by CFT renders worthwhile differences for health systems and patients. Trial registration number ClinicalTrials.gov registry (NCT02145728).
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Affiliation(s)
- Mary O'Keeffe
- Institute for Musculoskeletal Health, Sydney School of Public Health, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Peter O'Sullivan
- School of Physiotherapy and Exercise Science, Curtin University, Shenton Park, Perth, Western Australia, Australia.,Bodylogic Physiotherapy, Perth, Western Australia, Australia
| | - Helen Purtill
- Department of Mathematics & Statistics, Faculty of Science & Engineering, University of Limerick, Limerick, Ireland.,Health Research Institute, University of Limerick, Limerick, Ireland.,Aging Research Centre, University of Limerick, Limerick, Ireland
| | - Norma Bargary
- Department of Mathematics & Statistics, Faculty of Science & Engineering, University of Limerick, Limerick, Ireland.,Health Research Institute, University of Limerick, Limerick, Ireland
| | - Kieran O'Sullivan
- Health Research Institute, University of Limerick, Limerick, Ireland.,Aging Research Centre, University of Limerick, Limerick, Ireland.,Sports Spine Centre, Aspetar Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.,School of Allied Health, Faculty of Education and Health Sciences, University of Limerick, Limerick, Ireland
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74
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Winkelbeiner S, Leucht S, Kane JM, Homan P. Evaluation of Differences in Individual Treatment Response in Schizophrenia Spectrum Disorders: A Meta-analysis. JAMA Psychiatry 2019; 76:1063-1073. [PMID: 31158853 PMCID: PMC6547253 DOI: 10.1001/jamapsychiatry.2019.1530] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
IMPORTANCE An assumption among clinicians and researchers is that patients with schizophrenia vary considerably in their response to antipsychotic drugs in randomized clinical trials (RCTs). OBJECTIVE To evaluate the overall variation in individual treatment response from random variation by comparing the variability between treatment and control groups. DATA SOURCES Cochrane Schizophrenia, MEDLINE/PubMed, Embase, PsycINFO, Cochrane CENTRAL, BIOSIS Previews, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform from January 1, 1955, to December 31, 2016. STUDY SELECTION Double-blind, placebo-controlled, RCTs of adults with a diagnosis of schizophrenia spectrum disorders and prescription for licensed antipsychotic drugs. DATA EXTRACTION AND SYNTHESIS Means and SDs of the Positive and Negative Syndrome Scale pretreatment and posttreatment outcome difference scores were extracted. Data quality and validity were ensured by following the PRISMA guidelines. MAIN OUTCOMES AND MEASURES The outcome measure was the overall variability ratio of treatment to control in a meta-analysis across RCTs. Individual variability ratios were weighted by the inverse-variance method and entered into a random-effects model. A personal element of response was hypothesized to be reflected by a substantial overall increase in variability in the treatment group compared with the control group. RESULTS An RCT was simulated, comprising 30 patients with schizophrenia randomized to either the treatment or the control group. The different components of variation in RCTs were illustrated with simulated data. In addition, we assessed the variability ratio in 52 RCTs involving 15 360 patients with a schizophrenia or schizoaffective diagnosis. The variability was slightly lower in the treatment compared with the control group (variability ratio = 0.97; 95% CI, 0.95-0.99; P = .01). CONCLUSIONS AND RELEVANCE In this study, no evidence was found in RCTs that antipsychotic drugs increased the outcome variance, suggesting no personal element of response to treatment but instead indicating that the variance was slightly lower in the treatment group than in the control group; although the study cannot rule out that subsets of patients respond differently to treatment, it suggests that the average treatment effect is a reasonable assumption for the individual patient.
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Affiliation(s)
- Stephanie Winkelbeiner
- Center for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, New York,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, New York,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, New York,University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
| | - Stefan Leucht
- Department of Psychiatry and Psychotherapy, Technische Universität München, Munich, Germany
| | - John M. Kane
- Center for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, New York,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, New York,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, New York
| | - Philipp Homan
- Center for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, New York,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, New York,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, New York
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75
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Califf RM. Future of Personalized Cardiovascular Medicine: JACC State-of-the-Art Review. J Am Coll Cardiol 2019; 72:3301-3309. [PMID: 30573033 DOI: 10.1016/j.jacc.2018.09.079] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/05/2018] [Accepted: 09/24/2018] [Indexed: 11/28/2022]
Abstract
Previous decades have seen significant progress in the biological understanding of cardiovascular disease, as well as major advances in computational and information technologies. However, anticipated improvements in outcomes, quality, and cost of cardiovascular medicine at the individual and population levels from these advances have lagged expectations. Further, trends showing widening gaps in the pace of technological development and its successful uptake and application in practice suggests that substantial systemic changes are needed. Recent declines in key U.S. health outcomes have added further urgency to seek scalable approaches that deliver the right treatment to the right patient and to develop information-driven policies that improve health. The clinical care and research enterprises are currently in the midst of assimilating changes entrained by a "fourth industrial revolution" marked by the convergence of biology, physical sciences, and information science. These changes, if managed appropriately, can simultaneously enable cost-effective personalized medical care as well as more effective and targeted population health interventions. In this paper derived from a lecture in honor of cardiologist Paul Dudley White, the author explores how White's prescient insights into prevention and treatment continue to resonate today as we seek to assimilate ubiquitous computing, sophisticated sensor technologies, and bidirectional digital communication into the practice of cardiology. How the ongoing acceleration in basic science and information technologies can be wedded to the principles articulated by White as we pursue scalable approaches to personalized medicine is also examined.
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Affiliation(s)
- Robert M Califf
- Duke Forge, Duke University School of Medicine, Durham, North Carolina; Verily Life Sciences (Alphabet), South San Francisco, California; Stanford University Department of Medicine, Stanford, California.
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76
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Shun-Shin MJ, Miyazawa AA, Keene D, Sterliński M, Sokal A, Van Heuverswyn F, Rinaldi CA, Cornelussen R, Stegemann B, Francis DP, Whinnett Z. How to deliver personalized cardiac resynchronization therapy through the precise measurement of the acute hemodynamic response: Insights from the iSpot trial. J Cardiovasc Electrophysiol 2019; 30:1610-1619. [PMID: 31115945 DOI: 10.1111/jce.14001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 05/17/2019] [Accepted: 05/19/2019] [Indexed: 12/01/2022]
Abstract
INTRODUCTION New pacing technologies offer a greater choice of left ventricular pacing sites and greater personalization of cardiac resynchronization therapy (CRT). The effects on cardiac function of novel pacing configurations are often compared using multi-beat averages of acute hemodynamic measurements. In this analysis of the iSpot trial, we explore whether this is sufficient. MATERIALS AND METHODS The iSpot trial was an international, prospective, acute hemodynamic trial that assessed seven CRT configurations: standard CRT, MultiSpot (posterolateral vein), and MultiVein (anterior and posterior vein) pacing. Invasive and noninvasive blood pressure, and left ventricular (LV) dP/dtmax were recorded. Eight beats were recorded before and after an alternation from AAI to the tested pacing configuration and vice-versa. Eight alternations were performed for each configuration at each of the five atrioventricular delays. RESULTS Twenty-five patients underwent the full protocol of eight alternations. Only four (16%) patients had a statistically significant >3 mm Hg improvement over conventional CRT configuration (posterolateral vein, distal electrode). However, if only one alternation was analyzed (standard multi-beat averaging protocol), 15 (60%) patients falsely appeared to have a superior nonconventional configuration. Responses to pacing were significantly correlated between the different hemodynamic measures: invasive systolic blood pressure (SBP) vs noninvasive SBP r = 0.82 (P < .001); invasive SBP vs LV dP/dt r = 0.57, r2 = 0.32 (P < .001). CONCLUSIONS Current standard multibeat acquisition protocols are unfortunately unable to prevent false impressions of optimality arising in individual patients. Personalization processes need to include distinct repeated transitions to the tested pacing configuration in addition to averaging multiple beats. The need is not only during research stages but also during clinical implementation.
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Affiliation(s)
- Matthew J Shun-Shin
- International Centre for Circulatory Health, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Alejandra A Miyazawa
- International Centre for Circulatory Health, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Daniel Keene
- International Centre for Circulatory Health, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Maciej Sterliński
- The Second Department of Coronary Artery Disease, Institute of Cardiology, Warsaw, Poland
| | - Adam Sokal
- Department of Cardiology, Congenital Heart Diseases and Electrotherapy, Silesian Center of Heart Disease, Zabrze, Poland
| | | | | | - Richard Cornelussen
- Bakken Research Center B.V., Research and Technology, Maastricht, The Netherlands
| | - Berthold Stegemann
- Bakken Research Center B.V., Research and Technology, Maastricht, The Netherlands
| | - Darrel P Francis
- International Centre for Circulatory Health, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Zachary Whinnett
- International Centre for Circulatory Health, Imperial College London, Hammersmith Hospital, London, United Kingdom
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77
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Goltz FR, Thackray AE, Atkinson G, Lolli L, King JA, Dorling JL, Dowejko M, Mastana S, Stensel DJ. True Interindividual Variability Exists in Postprandial Appetite Responses in Healthy Men But Is Not Moderated by the FTO Genotype. J Nutr 2019; 149:1159-1169. [PMID: 31132105 PMCID: PMC6602891 DOI: 10.1093/jn/nxz062] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/05/2019] [Accepted: 03/11/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND After meal ingestion, a series of coordinated hormone responses occur concomitantly with changes in perceived appetite. It is not known whether interindividual variability in appetite exists in response to a meal. OBJECTIVES The aim of this study was to 1) assess the reproducibility of appetite responses to a meal; 2) quantify individual differences in responses; and 3) explore any moderating influence of the fat mass and obesity associated (FTO) gene. METHODS Using a replicated crossover design, 18 healthy men (mean ± SD age: 28.5 ± 9.8 y; BMI: 27.0 ± 5.0 kg/m2) recruited according to FTO genotype (9 AA, 9 TT) completed 2 identical control and 2 identical standardized meal conditions (5025 kJ) in randomized sequences. Perceived appetite and plasma acylated ghrelin, total peptide YY (PYY), insulin, and glucose concentrations were measured before and after interventions as primary outcomes. Interindividual differences were explored using Pearson's product-moment correlations between the first and second replicates of the control-adjusted meal response. Within-participant covariate-adjusted linear mixed models were used to quantify participant-by-condition and genotype-by-condition interactions. RESULTS The meal suppressed acylated ghrelin and appetite perceptions [standardized effect size (ES): 0.18-4.26] and elevated total PYY, insulin, and glucose (ES: 1.96-21.60). For all variables, SD of change scores was greater in the meal than in the control conditions. Moderate-to-large positive correlations were observed between the 2 replicates of control-adjusted meal responses for all variables (r = 0.44-0.86, P ≤ 0.070). Participant-by-condition interactions were present for all variables (P ≤ 0.056). FTO genotype-by-condition interactions were nonsignificant (P ≥ 0.19) and treatment effect differences between genotype groups were small (ES ≤ 0.27) for all appetite parameters. CONCLUSIONS Reproducibility of postprandial appetite responses is generally good. True interindividual variability is present beyond any random within-subject variation in healthy men but we detected no moderation by the FTO genotype. These findings highlight the importance of exploring individual differences in appetite for the prevention and treatment of obesity. This trial was registered at clinicaltrials.gov as NCT03771690.
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Affiliation(s)
- Fernanda R Goltz
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom,University Hospitals of Leicester National Health Service Trust, Leicester, United Kingdom
| | - Alice E Thackray
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom,University Hospitals of Leicester National Health Service Trust, Leicester, United Kingdom
| | - Greg Atkinson
- School of Health and Social Care, Teesside University, Middlesbrough, United Kingdom
| | - Lorenzo Lolli
- School of Health and Social Care, Teesside University, Middlesbrough, United Kingdom
| | - James A King
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom,University Hospitals of Leicester National Health Service Trust, Leicester, United Kingdom
| | - James L Dorling
- Ingestive Behavior Laboratory, Pennington Biomedical Research Center, Baton Rouge, LA
| | - Monika Dowejko
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - Sarabjit Mastana
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom
| | - David J Stensel
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise, and Health Sciences, Loughborough University, Loughborough, United Kingdom,University Hospitals of Leicester National Health Service Trust, Leicester, United Kingdom,Address correspondence to DJS (e-mail: )
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78
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Gewandter JS, McDermott MP, He H, Gao S, Cai X, Farrar JT, Katz NP, Markman JD, Senn S, Turk DC, Dworkin RH. Demonstrating Heterogeneity of Treatment Effects Among Patients: An Overlooked but Important Step Toward Precision Medicine. Clin Pharmacol Ther 2019; 106:204-210. [PMID: 30661240 PMCID: PMC6784315 DOI: 10.1002/cpt.1372] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/06/2019] [Indexed: 01/11/2023]
Abstract
Although heterogeneity in the observed outcomes in clinical trials is often assumed to reflect a true heterogeneous response, it could actually be due to random variability. This retrospective analysis of four randomized, double-blind, placebo-controlled multiperiod (i.e., episode) crossover trials of fentanyl for breakthrough cancer pain illustrates the use of multiperiod crossover trials to examine heterogeneity of treatment response. A mixed-effects model, including fixed effects for treatment and episode and random effects for patient and treatment-by-patient interaction, was used to assess the heterogeneity in patients' responses to treatment during each episode. A significant treatment-by-patient interaction was found for three of four trials (P < 0.05), suggesting heterogeneity of the effect of fentanyl among different patients in each trial. Similar analyses in other therapeutic areas could identify conditions and therapies that should be investigated further for predictors of treatment response in efforts to maximize the efficiency of developing precision medicine strategies.
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Affiliation(s)
- Jennifer S. Gewandter
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester NY, USA
| | - Michael P. McDermott
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester NY, USA
| | - Hua He
- Department of Epidemiology, Tulane, New Orleans LA, USA
| | - Shan Gao
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester NY, USA
| | - Xueya Cai
- Department of Biostatistics and Computational Biology, University of Rochester, Rochester NY, USA
| | - John T. Farrar
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Nathaniel P. Katz
- Analgesic Solutions, Natick, MA, USA; Tufts University School of Medicine, Boston, MA, USA
| | - John D. Markman
- Department of Neurosurgery, University of Rochester, Rochester NY, USA
| | - Stephen Senn
- Luxembourg Institute of Health, Strassen, Luxembourg
| | - Dennis C. Turk
- Department of Anesthesiology & Pain Medicine, University of Washington, Seattle, Washington, USA
| | - Robert H. Dworkin
- Department of Anesthesiology and Perioperative Medicine, University of Rochester, Rochester NY, USA
- Department of Neurosurgery, University of Rochester, Rochester NY, USA
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79
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Atkinson G, Williamson P, Batterham AM. Issues in the determination of 'responders' and 'non-responders' in physiological research. Exp Physiol 2019; 104:1215-1225. [PMID: 31116468 DOI: 10.1113/ep087712] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 05/21/2019] [Indexed: 01/06/2023]
Abstract
NEW FINDINGS What is the topic for this review? We discuss the dichotomization of continuous-level physiological measurements into 'responders' and 'non-responders' when interventions/treatments are examined in robust parallel-group studies. What advances does it highlight? Sample responder counts are biased by pre-to-post within-subject variability. Sample differences in counts may be explained wholly by differences in mean response, even without individual response heterogeneity and even if test-retest measurement error informs the choice of response threshold. A less biased and more informative approach uses the SD of individual responses to estimate the chance a new person from the population of interest will be a responder. ABSTRACT As a follow-up to our 2015 review, we cover more issues on the topic of 'response heterogeneity', which we define as clinically important individual differences in the physiological responses to the same treatment/intervention that cannot be attributed to random within-subject variability. We highlight various pitfalls with the common practice of counting the number of 'responders', 'non-responders' and 'adverse responders' in samples that have been given certain treatments or interventions for research purposes. We focus on the classical parallel-group randomized controlled trial and assume typical good practice in trial design. We show that sample responder counts are biased because individuals differ in terms of pre-to-post within-subject random variability in the study outcome(s) and not necessarily treatment response. Ironically, sample differences in responder counts may be explained wholly by sample differences in mean response, even if there is no response heterogeneity at all. Sample comparisons of responder counts also have relatively low statistical precision. These problems do not depend on how the response threshold has been selected, e.g. on the basis of a measurement error statistic, and are not rectified fully by the use of confidence intervals for individual responses in the sample. The dichotomization of individual responses in a research sample is fraught with pitfalls. Less biased approaches for estimating the proportion of responders in a population of interest are now available. Importantly, these approaches are based on the SD for true individual responses, directly incorporating information from the control group.
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Affiliation(s)
- Greg Atkinson
- School of Health and Social Care, Teesside University, Middlesbrough, UK
| | - Philip Williamson
- Faculty of Health Sciences, School of Life Sciences, University of Hull, Hull, UK
| | - Alan M Batterham
- School of Health and Social Care, Teesside University, Middlesbrough, UK
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80
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Plastic diagnostics: The remaking of disease and evidence in personalized medicine. Soc Sci Med 2019; 304:112318. [PMID: 31130237 PMCID: PMC9218799 DOI: 10.1016/j.socscimed.2019.05.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 12/15/2022]
Abstract
Politically authorized reports on personalized and precision medicine stress an urgent need for finer-grained disease categories and faster taxonomic revision, through integration of genomic and phenotypic data. Developing a data-driven taxonomy is, however, not as simple as it sounds. It is often assumed that an integrated data infrastructure is relatively easy to implement in countries that already have highly centralized and digitalized health care systems. Our analysis of initiatives associated with the Danish National Genome Center, recently launched to bring Denmark to the forefront of personalized medicine, tells a different story. Through a “meta-taxonomy” of taxonomic revisions, we discuss what a genomics-based disease taxonomy entails, epistemically as well as organizationally. Whereas policy reports promote a vision of seamless data integration and standardization, we highlight how the envisioned strategy imposes significant changes on the organization of health care systems. Our analysis shows how persistent tensions in medicine between variation and standardization, and between change and continuity, remain obstacles for the production as well as the evaluation of genomics-based taxonomies of difference. We identify inherent conflicts between the ideal of dynamic revision and existing regulatory functions of disease categories in, for example, the organization and management of health care systems. Moreover, we raise concerns about shifts in the regulatory regime of evidence standards, where clinical care increasingly becomes a vehicle for biomedical research. Personalized medicine has led to calls for speedy revisions of disease taxonomies. A “meta-taxonomy” of disease taxonomic revisions is presented and discussed. Fine-graining disease categories has regulatory implications for healthcare systems. A Danish case illustrates difficulties in aligning multiple functions of disease codes. We argue that the political call for speed should be treated with caution.
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Santhakumaran S, Gordon A, Prevost AT, O'Kane C, McAuley DF, Shankar-Hari M. Heterogeneity of treatment effect by baseline risk of mortality in critically ill patients: re-analysis of three recent sepsis and ARDS randomised controlled trials. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2019; 23:156. [PMID: 31053084 PMCID: PMC6500045 DOI: 10.1186/s13054-019-2446-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/15/2019] [Indexed: 01/15/2023]
Abstract
Background Randomised controlled trials (RCTs) enrolling patients with sepsis or acute respiratory distress syndrome (ARDS) generate heterogeneous trial populations. Non-random variation in the treatment effect of an intervention due to differences in the baseline risk of death between patients in a population represents one form of heterogeneity of treatment effect (HTE). We assessed whether HTE in two sepsis and one ARDS RCTs could explain indeterminate trial results and inform future trial design. Methods We assessed HTE for vasopressin, hydrocortisone and levosimendan in sepsis and simvastatin in ARDS patients, on 28-day mortality, using the total Acute Physiology And Chronic Health Evaluation II (APACHE II) score as the baseline risk measurement, comparing above (high) and below (low) the median score. Secondary risk measures were the acute physiology component of APACHE II and predicted risk of mortality using the APACHE II score. HTE was quantified both in additive (difference in risk difference (RD)) and multiplicative (ratio of relative risks (RR)) scales using estimated treatment differences from a logistic regression model with treatment risk as the interaction term. Results The ratio of the odds of death in the highest APACHE II quartile was 4.9 to 7.4 times compared to the lowest quartile, across the three trials. We did not observe HTE for vasopressin, hydrocortisone and levosimendan in the two sepsis trials. In the HARP-2 trial, simvastatin reduced mortality in the low APACHE II group and increased mortality in the high APACHE II group (difference in RD = 0.34 (0.12, 0.55) (p = 0.02); ratio of RR 3.57 (1.77, 7.17) (p < 0.001). The HTE patterns were inconsistent across the secondary risk measures. The sensitivity analyses of HTE effects for vasopressin, hydrocortisone and levosimendan were consistent with the main analyses and attenuated for simvastatin. Conclusions We assessed HTE in three recent ICU RCTs, using multivariable baseline risk of death models. There was considerable within-trial variation in the baseline risk of death. We observed potential HTE for simvastatin in ARDS, but no evidence of HTE for vasopressin, hydrocortisone or levosimendan in the two sepsis trials. Our findings could be explained either by true lack of HTE (no benefit of vasopressin, hydrocortisone or levosimendan vs comparator for any patient subgroups) or by lack of power to detect HTE. Our results require validation using similar trial databases. Electronic supplementary material The online version of this article (10.1186/s13054-019-2446-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shalini Santhakumaran
- Imperial Clinical Trials Unit, School of Public Health, Imperial College London, London, W12 7RH, UK
| | - Anthony Gordon
- Section of Anaesthetics, Pain Medicine and Intensive Care, Imperial College London, London, W2 1NY, UK
| | - A Toby Prevost
- Imperial Clinical Trials Unit, School of Public Health, Imperial College London, London, W12 7RH, UK
| | - Cecilia O'Kane
- Centre for Experimental Medicine, Wellcome-Wolfson Institute for Experimental Medicine, Belfast, BT9 7AE, UK
| | - Daniel F McAuley
- Centre for Experimental Medicine, Wellcome-Wolfson Institute for Experimental Medicine, Belfast, BT9 7AE, UK.,Regional Intensive Care Unit, Royal Victoria Hospital, Belfast, BT12 6BA, UK
| | - Manu Shankar-Hari
- Department of Intensive Care Medicine, St Thomas' Hospital, Guy's and St Thomas' NHS Foundation Trust , Westminster Bridge Road, London, SE1 7EH, UK. .,Peter Gorer Department of Immunobiology, School of Immunology & Microbial Sciences, King's College London, London, SE1 9RT, UK.
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Homan P, Argyelan M, DeRosse P, Szeszko PR, Gallego JA, Hanna L, Robinson DG, Kane JM, Lencz T, Malhotra AK. Structural similarity networks predict clinical outcome in early-phase psychosis. Neuropsychopharmacology 2019; 44:915-922. [PMID: 30679724 PMCID: PMC6461949 DOI: 10.1038/s41386-019-0322-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/17/2018] [Accepted: 01/16/2019] [Indexed: 02/06/2023]
Abstract
Despite recent advances, there is still a major need for prediction of treatment success in schizophrenia, a condition long considered a disorder of dysconnectivity in the brain. Graph theory provides a means to characterize the connectivity in both healthy and abnormal brains. We calculated structural similarity networks in each participant and hypothesized that the "hubness", i.e., the number of edges connecting a node to the rest of the network, would be associated with clinical outcome. This prospective controlled study took place at an academic research center and included 82 early-phase psychosis patients (23 females; mean age [SD] = 21.6 [5.5] years) and 58 healthy controls. Medications were administered in a double-blind randomized manner, and patients were scanned at baseline prior to treatment with second-generation antipsychotics. Symptoms were assessed with the Brief Psychiatric Rating Scale at baseline and over the course of 12 weeks. Nodal degree of structural similarity networks was computed for each subject and entered as a predictor of individual treatment response into a partial least squares (PLS) regression. The model fit was significant in a permutation test with 1000 permutations (P = 0.006), and the first two PLS regression components explained 29% (95% CI: 27; 30) of the variance in treatment response after cross-validation. Nodes loading strongly on the first PLS component were primarily located in the orbito- and prefrontal cortex, whereas nodes loading strongly on the second PLS component were primarily located in the superior temporal, precentral, and middle cingulate cortex. These data suggest a link between brain network morphology and clinical outcome in early-phase psychosis.
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Affiliation(s)
- Philipp Homan
- Center for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY, USA. .,Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY, USA. .,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA.
| | - Miklos Argyelan
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
| | - Pamela DeRosse
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
| | - Philip R. Szeszko
- 0000 0004 0420 1184grid.274295.fJames J. Peters Veterans Affairs Medical Center, Bronx, NY USA
| | - Juan A. Gallego
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
| | - Lauren Hanna
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
| | - Delbert G. Robinson
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
| | - John M. Kane
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
| | - Todd Lencz
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
| | - Anil K. Malhotra
- 0000 0000 9566 0634grid.250903.dCenter for Psychiatric Neuroscience, Feinstein Institute for Medical Research, Manhasset, NY USA ,0000 0001 2168 3646grid.416477.7Division of Psychiatry Research, Zucker Hillside Hospital, Northwell Health, New York, NY USA ,Department of Psychiatry, Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY USA
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83
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Ross R, Goodpaster BH, Koch LG, Sarzynski MA, Kohrt WM, Johannsen NM, Skinner JS, Castro A, Irving BA, Noland RC, Sparks LM, Spielmann G, Day AG, Pitsch W, Hopkins WG, Bouchard C. Precision exercise medicine: understanding exercise response variability. Br J Sports Med 2019; 53:1141-1153. [PMID: 30862704 PMCID: PMC6818669 DOI: 10.1136/bjsports-2018-100328] [Citation(s) in RCA: 142] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2019] [Indexed: 12/14/2022]
Abstract
There is evidence from human twin and family studies as well as mouse and rat selection experiments that there are considerable interindividual differences in the response of cardiorespiratory fitness (CRF) and other cardiometabolic traits to a given exercise programme dose. We developed this consensus statement on exercise response variability following a symposium dedicated to this topic. There is strong evidence from both animal and human studies that exercise training doses lead to variable responses. A genetic component contributes to exercise training response variability. In this consensus statement, we (1) briefly review the literature on exercise response variability and the various sources of variations in CRF response to an exercise programme, (2) introduce the key research designs and corresponding statistical models with an emphasis on randomised controlled designs with or without multiple pretests and post-tests, crossover designs and repeated measures designs, (3) discuss advantages and disadvantages of multiple methods of categorising exercise response levels—a topic that is of particular interest for personalised exercise medicine and (4) outline approaches that may identify determinants and modifiers of CRF exercise response. We also summarise gaps in knowledge and recommend future research to better understand exercise response variability.
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Affiliation(s)
- Robert Ross
- School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada
| | - Bret H Goodpaster
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, Florida, USA
| | - Lauren G Koch
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Mark A Sarzynski
- Department of Exercise Science, University of South Carolina, Columbia, South Carolina, USA
| | - Wendy M Kohrt
- Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Neil M Johannsen
- Interventional Resources, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA.,School of Kinesiology, Louisiana State University, Baton Rouge, Louisiana, USA
| | - James S Skinner
- Department of Kinesiology, Indiana University, Bloomington, Indiana, USA
| | - Alex Castro
- Department of Physical Education, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Brian A Irving
- School of Kinesiology, Louisiana State University, Baton Rouge, Louisiana, USA.,Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Robert C Noland
- John S Mcilhenny Skeletal Muscle Physiology Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Lauren M Sparks
- Translational Research Institute for Metabolism and Diabetes, Florida Hospital, Orlando, Florida, USA
| | - Guillaume Spielmann
- School of Kinesiology, Louisiana State University, Baton Rouge, Louisiana, USA.,Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Andrew G Day
- Kingston General Health Research Institute, Kingston Health Sciences Centre, Kingston, Ontario, Canada
| | - Werner Pitsch
- Economics and Sociology of Sport, Saarland University, Saarbrücken, Saarland, Germany
| | - William G Hopkins
- College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia
| | - Claude Bouchard
- Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
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84
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Protect us from poor-quality medical research. Hum Reprod 2019; 33:770-776. [PMID: 29617882 DOI: 10.1093/humrep/dey056] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/01/2018] [Indexed: 01/22/2023] Open
Abstract
Much of the published medical research is apparently flawed, cannot be replicated and/or has limited or no utility. This article presents an overview of the current landscape of biomedical research, identifies problems associated with common study designs and considers potential solutions. Randomized clinical trials, observational studies, systematic reviews and meta-analyses are discussed in terms of their inherent limitations and potential ways of improving their conduct, analysis and reporting. The current emphasis on statistical significance needs to be replaced by sound design, transparency and willingness to share data with a clear commitment towards improving the quality and utility of clinical research.
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85
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Goltz FR, Thackray AE, King JA, Dorling JL, Atkinson G, Stensel DJ. Interindividual Responses of Appetite to Acute Exercise: A Replicated Crossover Study. Med Sci Sports Exerc 2019; 50:758-768. [PMID: 29240652 DOI: 10.1249/mss.0000000000001504] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE Acute exercise transiently suppresses appetite, which coincides with alterations in appetite-regulatory hormone concentrations. Individual variability in these responses is suspected, but replicated trials are needed to quantify them robustly. We examined the reproducibility of appetite and appetite-regulatory hormone responses to acute exercise and quantified the individual differences in responses. METHODS Fifteen healthy, recreationally active men completed two control (60-min resting) and two exercise (60-min fasted treadmill running at 70% peak oxygen uptake) conditions in randomized sequences. Perceived appetite and circulating concentrations of acylated ghrelin and total peptide YY (PYY) were measured immediately before and after the interventions. Interindividual differences were explored by correlating the two sets of response differences between exercise and control conditions. Within-participant covariate-adjusted linear mixed models were used to quantify participant-condition interactions. RESULTS Compared with control, exercise suppressed mean acylated ghrelin concentrations and appetite perceptions (all ES = 0.62-1.47, P < 0.001) and elevated total PYY concentrations (ES = 1.49, P < 0.001). For all variables, the standard deviation of the change scores was substantially greater in the exercise versus control conditions. Moderate-to-large positive correlations were observed between the two sets of control-adjusted exercise responses for all variables (r = 0.54-0.82, P ≤ 0.036). After adjusting for baseline measurements, participant-condition interactions were present for all variables (P ≤ 0.053). CONCLUSIONS Our replicated crossover study allowed, for the first time, the interaction between participant and acute exercise response in appetite parameters to be quantified. Even after adjustment for individual baseline measurements, participants demonstrated individual differences in perceived appetite and hormone responses to acute exercise bouts beyond any random within-subject variability over time.
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Affiliation(s)
- Fernanda R Goltz
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM
| | - Alice E Thackray
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM
| | - James A King
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM
| | - James L Dorling
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM
| | - Greg Atkinson
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM
| | - David J Stensel
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM.,National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UNITED KINGDOM
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86
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Voisin S, Jacques M, Lucia A, Bishop DJ, Eynon N. Statistical Considerations for Exercise Protocols Aimed at Measuring Trainability. Exerc Sport Sci Rev 2019; 47:37-45. [PMID: 30334853 DOI: 10.1249/jes.0000000000000176] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The individual response to exercise training is of great interest with methods that have been proposed to measure this response reviewed in this paper. However, individual training response estimates may be biased by various sources of variability present in exercise studies, and in particular by within-subject variability. We propose the use of protocols that can separate trainability from within-subject variability.
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Affiliation(s)
- Sarah Voisin
- Institute for Health and Sport (iHeS), Victoria University, Victoria, Australia
| | - Macsue Jacques
- Institute for Health and Sport (iHeS), Victoria University, Victoria, Australia
| | - Alejandro Lucia
- European University of Madrid (Faculty of Sports Sciences) and Research Institute 'i+12'.,Biomedical Research Centre, Network of Frailty and Healthy Aging, Madrid, Spain
| | - David J Bishop
- Institute for Health and Sport (iHeS), Victoria University, Victoria, Australia.,School of Medical and Health Sciences, Edith Cowan University, Joondalup
| | - Nir Eynon
- Institute for Health and Sport (iHeS), Victoria University, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Australia
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87
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Sundström J, Lind L, Nowrouzi S, Lytsy P, Marttala K, Ekman I, Öhagen P, Östlund O. The Precision HYpertenSIon Care (PHYSIC) study: a double-blind, randomized, repeated cross-over study. Ups J Med Sci 2019; 124:51-58. [PMID: 30265168 PMCID: PMC6450492 DOI: 10.1080/03009734.2018.1498958] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
High blood pressure is the leading risk factor for premature deaths and a major cost to societies worldwide. Effective blood pressure-lowering drugs are available, but patient adherence to them is low, likely partly due to side effects. To identify patient-specific differences in treatment effects, a repeated cross-over design, where the same treatment contrasts are repeated within each patient, is needed. Such designs have been surprisingly rarely used, given the current focus on precision medicine. The Precision HYpertenSIon Care (PHYSIC) study aims to investigate if there is a consistent between-person variation in blood pressure response to the common blood pressure-lowering drug classes of a clinically relevant magnitude, given the within-person variation in blood pressure. The study will also investigate the between-person variation in side effects of the drugs. In a double-blind, randomized, repeated cross-over trial, 300 patients with mild hypertension will be treated with four blood pressure-lowering drugs (candesartan, lisinopril, amlodipine, and hydrochlorothiazide) in monotherapy, with two of the drugs repeated for each patient. If the study indicates that there is a potential for precision hypertension care, the most promising predictors of blood pressure and side effect response to the drugs will be explored, as will the potential for development of a biomarker panel to rank the suitability of blood pressure-lowering drug classes for individual patients in terms of anticipated blood pressure effects and side effects, with the ultimate goal to maximize adherence. The study follows a protocol pre-registered at ClinicalTrials.gov with the identifier NCT02774460.
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Affiliation(s)
- Johan Sundström
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Uppsala Clinical Research Center (UCR), Uppsala, Sweden
- CONTACT Johan Sundström Uppsala University, Department of Medical Sciences, Uppsala, Sweden. E-mail:
| | - Lars Lind
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Shamim Nowrouzi
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Per Lytsy
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Kerstin Marttala
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Inger Ekman
- Uppsala Clinical Research Center (UCR), Uppsala, Sweden
| | - Patrik Öhagen
- Uppsala Clinical Research Center (UCR), Uppsala, Sweden
| | - Ollie Östlund
- Uppsala Clinical Research Center (UCR), Uppsala, Sweden
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88
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89
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Porcher R, Jacot J, Wunder JS, Biau DJ. Identifying treatment responders using counterfactual modeling and potential outcomes. Stat Methods Med Res 2018; 28:3346-3362. [PMID: 30298794 DOI: 10.1177/0962280218804569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Individualizing treatment according to patients' characteristics is central for personalized or precision medicine. There has been considerable recent research in developing statistical methods to determine optimal personalized treatment strategies by modeling the outcome of patients according to relevant covariates under each of the alternative treatments, and then relying on so-called predicted individual treatment effects. In this paper, we use potential outcomes and principal stratification frameworks and develop a multinomial model for left and right-censored data to estimate the probability that a patient is a responder given a set of baseline covariates. The model can apply to RCT or observational study data. This method is based on the monotonicity assumption, which implies that no patients would respond to the control treatment but not to the experimental one. We conduct a simulation study to evaluate the properties of the proposed estimation method. Results showed that the predictions of the probability of being a responder were well calibrated even if we observed variability and a small bias when many parameters were estimated. We finally applied the method to a cohort study on the selection of patients for additional radiotherapy after resection of a soft-tissue sarcoma.
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Affiliation(s)
- Raphaël Porcher
- Faculté de Médecine, Université Paris Decartes, Sorbonne Paris Cité, Paris, France.,Centre de Recherche Epidémiologie et Statistiques, INSERM U1153, Paris, France.,Centre d'Epidémiologie Clinique, Hôtel-dieu, Assistance Publique-Hôpitzaux de Paris, France
| | - Justine Jacot
- Centre de Recherche Epidémiologie et Statistiques, INSERM U1153, Paris, France.,Centre d'Epidémiologie Clinique, Hôtel-dieu, Assistance Publique-Hôpitzaux de Paris, France
| | - Jay S Wunder
- University Musculoskeletal Oncology Unit, Mount Sinai Hospital, Canada.,Division of Orthopaedic Surgery, Department of Surgery, University of Toronto, Canada
| | - David J Biau
- Faculté de Médecine, Université Paris Decartes, Sorbonne Paris Cité, Paris, France.,Centre de Recherche Epidémiologie et Statistiques, INSERM U1153, Paris, France.,Département de Chirurgie Orthopédique, Hôpital Cochin, Assistance Publique-Hôpitaux de Paris, France
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90
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Affiliation(s)
- P Homan
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Manhasset, NY, USA.,Division of Psychiatry Research, The Zucker Hillside Hospital, Northwell Health, New York, NY, USA.,Department of Psychiatry, The Donald and Barbara Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA
| | - J M Kane
- Center for Psychiatric Neuroscience, The Feinstein Institute for Medical Research, Manhasset, NY, USA.,Division of Psychiatry Research, The Zucker Hillside Hospital, Northwell Health, New York, NY, USA.,Department of Psychiatry, The Donald and Barbara Zucker School of Medicine at Northwell/Hofstra, Hempstead, NY, USA
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91
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Hecksteden A, Faude O, Meyer T, Donath L. How to Construct, Conduct and Analyze an Exercise Training Study? Front Physiol 2018; 9:1007. [PMID: 30140237 PMCID: PMC6094975 DOI: 10.3389/fphys.2018.01007] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/09/2018] [Indexed: 11/13/2022] Open
Abstract
Randomized controlled trials (RCTs) can be regarded as gold standard in investigating dose-response and causal relationships in exercise science. Recommendations for exercise training routines and efficacy analyses of certain training regimen require valid data derived from robust RCTs. Moreover, meta-analyses rely on RCTs and both RCTs and meta-analyses are considered the highest level of scientific evidence. Beyond general study design a variety of methodological aspects and notable pitfalls has to be considered. Therefore, exercise training studies should be carefully constructed focusing on the consistency of the whole design "package" from an explicit hypothesis or research question over study design and methodology to data analysis and interpretation. The present scoping review covers all main aspects of planning, conducting, and analyzing exercise based RCTs. We aim to focus on relevant aspects regarding study design, statistical power, training planning and documentation as well as traditional and recent statistical approaches. We intend to provide a comprehensive hands-on paper for conceptualizing future exercise training studies and hope to stimulate and encourage researchers to conduct sound and valid RCTs in the field of exercise training.
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Affiliation(s)
- Anne Hecksteden
- Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany
| | - Oliver Faude
- Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland
| | - Tim Meyer
- Institute of Sports and Preventive Medicine, Saarland University, Saarbrücken, Germany
| | - Lars Donath
- Department of Intervention Research in Exercise Training, German Sport University Cologne, Cologne, Germany
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92
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Williamson PJ, Atkinson G, Batterham AM. Inter-Individual Responses of Maximal Oxygen Uptake to Exercise Training: A Critical Review. Sports Med 2018; 47:1501-1513. [PMID: 28097487 DOI: 10.1007/s40279-017-0680-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
It has recently been reported how to quantify inter-individual differences in the response to an exercise intervention using the standard deviation of the change scores, as well as how to appraise these differences for clinical relevance. In a parallel-group randomised controlled trial, the key trigger for further investigation into inter-individual responses is when the standard deviation of change in the intervention sample is substantially larger than the same standard deviation derived from a suitable comparator sample. 'True' and clinically relevant inter-individual differences in response can then be plausibly expected, and potential moderators and mediators of the inter-individual differences can be explored. We now aim to critically review the research on the inter-individual differences in response to exercise training, focusing on maximal oxygen uptake (VO2max). A literature search through the relevant bibliographic databases resulted in the identification of six relevant studies that were published prior to the influential HEalth, RIsk factors, exercise Training And GEnetics (HERITAGE) Family Study. Only one of these studies was found to include a comparator arm. Re-analysis of the data from this study, accounting for random within-subjects variation, revealed an absence of clinically important inter-individual differences in the response of VO2max to exercise training. The standard deviation of change was, in fact, larger (±5.6 mL/kg/min) for the comparator than the intervention group (±3.7 mL/kg/min). We located over 180 publications that resulted from the HERITAGE Family Study, but we could not find a comparator arm in any of these studies. Some authors did not explain this absence, while others reasoned that only inter-individual differences in exercise response were of interest, thus the intervention sample was investigated solely. We also found this absence of a comparator sample in on-going studies. A perceived high test-retest reliability is offered as a justification for the absence of a comparator arm, but the test-retest reliability analysis for the HERITAGE Family Study was over a much shorter term than the length of the actual training period between baseline and follow-up measurements of VO2max. We also scrutinised the studies in which twins have been investigated, resulting in concerns about how genetic influences on the magnitude of general within-subjects variability has been partitioned out (again in the absence of a comparator no-training group), as well as with the intra-class correlation coefficient approach to data analysis. Twin pairs were found to be sometimes heterogeneous for the obviously influential factors of sex, age and fitness, thereby inflating an unadjusted coefficient. We conclude that most studies on inter-individual differences in VO2max response to exercise training have no comparator sample. Therefore, true inter-individual differences in response cannot be quantified, let alone appraised for clinical relevance. For those studies with a comparator sample, we found that the inter-individual differences in training response were not larger than random within-subjects variation in VO2max over the same time period as the training intervention.
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Affiliation(s)
- Philip J Williamson
- Health and Social Care Institute, Teesside University, Middlesbrough, TS1 3BX, UK.
| | - Greg Atkinson
- Health and Social Care Institute, Teesside University, Middlesbrough, TS1 3BX, UK
| | - Alan M Batterham
- Health and Social Care Institute, Teesside University, Middlesbrough, TS1 3BX, UK
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93
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Shankar-Hari M, Harrison DA, Rowan KM, Rubenfeld GD. Estimating attributable fraction of mortality from sepsis to inform clinical trials. J Crit Care 2018; 45:33-39. [DOI: 10.1016/j.jcrc.2018.01.018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/15/2018] [Accepted: 01/17/2018] [Indexed: 11/17/2022]
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94
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Hecksteden A, Pitsch W, Rosenberger F, Meyer T. Repeated testing for the assessment of individual response to exercise training. J Appl Physiol (1985) 2018; 124:1567-1579. [DOI: 10.1152/japplphysiol.00896.2017] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Observed response to regular exercise training differs widely between individuals even in tightly controlled research settings. However, the respective contributions of random error and true interindividual differences as well as the relative frequency of nonresponders are disputed. Specific challenges of analyses on the individual level as well as a striking heterogeneity in definitions may partly explain these inconsistent results. Repeated testing during the training phase specifically addresses the requirements of analyses on the individual level. Here we report a first implementation of this innovative design amendment in a head-to-head comparison of existing analytical approaches. To allow for comparative implementation of approaches we conducted a controlled endurance training trial (1 yr walking/jogging, 3 days/wk for 45 min with 60% heart rate reserve) in healthy, untrained subjects ( n = 36, age = 46 ± 8 yr; body mass index 24.7 ± 2.7 kg/m2; V̇o2max 36.6 ± 5.4). In the training group additional V̇o2max tests were conducted after 3, 6, and 9 mo. Duration of the control condition was 6 mo due to ethical constraints. General efficacy of the training intervention could be verified by a significant increase in V̇o2max in the training group ( P < 0.001 vs. control). Individual training response of relevant magnitude (>0.2 × baseline variability in V̇o2max) could be demonstrated by several approaches. Regarding the classification of individuals, only 11 of 20 subjects were consistently classified, demonstrating remarkable disagreement between approaches. These results are in support of relevant interindividual variability in training efficacy and stress the limitations of a responder classification. Moreover, this proof-of-concept underlines the need for tailored methodological approaches for well-defined problems. NEW & NOTEWORTHY This work reports a first implementation of a repeated testing training trial for the investigation of individual response. This design amendment was recently proposed to address specifically the statistical requirements of analyses on the individual level. Moreover, a comprehensive comparison of previously published methods exemplifies the striking heterogeneity of existing approaches.
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Affiliation(s)
- Anne Hecksteden
- Institute of Sports and Preventive Medicine, Saarland University, Saarbruecken, Germany
| | - Werner Pitsch
- Institute for Sport Sciences, Department of Sociology and Economics of Sports, Saarland University, Saarbruecken, Germany
| | - Friederike Rosenberger
- Heidelberg University Hospital, National Center for Tumor Diseases (NCT), Heidelberg, Germany
- German University of Applied Sciences for Prevention and Health Management (DHfPG), Saarbrücken, Germany
| | - Tim Meyer
- Institute of Sports and Preventive Medicine, Saarland University, Saarbruecken, Germany
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95
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Hilgers RD, Bogdan M, Burman CF, Dette H, Karlsson M, König F, Male C, Mentré F, Molenberghs G, Senn S. Lessons learned from IDeAl - 33 recommendations from the IDeAl-net about design and analysis of small population clinical trials. Orphanet J Rare Dis 2018; 13:77. [PMID: 29751809 PMCID: PMC5948846 DOI: 10.1186/s13023-018-0820-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 05/01/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND IDeAl (Integrated designs and analysis of small population clinical trials) is an EU funded project developing new statistical design and analysis methodologies for clinical trials in small population groups. Here we provide an overview of IDeAl findings and give recommendations to applied researchers. METHOD The description of the findings is broken down by the nine scientific IDeAl work packages and summarizes results from the project's more than 60 publications to date in peer reviewed journals. In addition, we applied text mining to evaluate the publications and the IDeAl work packages' output in relation to the design and analysis terms derived from in the IRDiRC task force report on small population clinical trials. RESULTS The results are summarized, describing the developments from an applied viewpoint. The main result presented here are 33 practical recommendations drawn from the work, giving researchers a comprehensive guidance to the improved methodology. In particular, the findings will help design and analyse efficient clinical trials in rare diseases with limited number of patients available. We developed a network representation relating the hot topics developed by the IRDiRC task force on small population clinical trials to IDeAl's work as well as relating important methodologies by IDeAl's definition necessary to consider in design and analysis of small-population clinical trials. These network representation establish a new perspective on design and analysis of small-population clinical trials. CONCLUSION IDeAl has provided a huge number of options to refine the statistical methodology for small-population clinical trials from various perspectives. A total of 33 recommendations developed and related to the work packages help the researcher to design small population clinical trial. The route to improvements is displayed in IDeAl-network representing important statistical methodological skills necessary to design and analysis of small-population clinical trials. The methods are ready for use.
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Affiliation(s)
- Ralf-Dieter Hilgers
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany.
| | - Malgorzata Bogdan
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - Carl-Fredrik Burman
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - Holger Dette
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - Mats Karlsson
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - Franz König
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - Christoph Male
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - France Mentré
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - Geert Molenberghs
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
| | - Stephen Senn
- Department of Medical Statistics, RWTH Aachen University, Pauwelsstr. 19, D-52074, Aachen, Germany
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96
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Gibson E, Bretz F, Looby M, Bornkamp B. Key Aspects of Modern, Quantitative Drug Development. STATISTICS IN BIOSCIENCES 2018. [DOI: 10.1007/s12561-017-9203-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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97
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Steinert T. Chance of response to an antidepressant: what should we say to the patient? World Psychiatry 2018; 17:114-115. [PMID: 29352537 PMCID: PMC5775148 DOI: 10.1002/wps.20511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Tilman Steinert
- Department of Psychiatry and Psychotherapy, Ulm University, Ulm; Centers for Psychiatry Suedwuerttemberg, Ravensburg, Baden-Wuerttemberg, Germany
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98
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Norbury A, Seymour B. Response heterogeneity: Challenges for personalised medicine and big data approaches in psychiatry and chronic pain. F1000Res 2018; 7:55. [PMID: 29527298 PMCID: PMC5820606 DOI: 10.12688/f1000research.13723.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/11/2018] [Indexed: 11/08/2023] Open
Abstract
Response rates to available treatments for psychological and chronic pain disorders are poor, and there is a considerable burden of suffering and disability for patients, who often cycle through several rounds of ineffective treatment. As individuals presenting to the clinic with symptoms of these disorders are likely to be heterogeneous, there is considerable interest in the possibility that different constellations of signs could be used to identify subgroups of patients that might preferentially benefit from particular kinds of treatment. To this end, there has been a recent focus on the application of machine learning methods to attempt to identify sets of predictor variables (demographic, genetic, etc.) that could be used to target individuals towards treatments that are more likely to work for them in the first instance. Importantly, the training of such models generally relies on datasets where groups of individual predictor variables are labelled with a binary outcome category - usually 'responder' or 'non-responder' (to a particular treatment). However, as previously highlighted in other areas of medicine, there is a basic statistical problem in classifying individuals as 'responding' to a particular treatment on the basis of data from conventional randomized controlled trials. Specifically, insufficient information on the partition of variance components in individual symptom changes mean that it is inappropriate to consider data from the active treatment arm alone in this way. This may be particularly problematic in the case of psychiatric and chronic pain symptom data, where both within-subject variability and measurement error are likely to be high. Here, we outline some possible solutions to this problem in terms of dataset design and machine learning methodology, and conclude that it is important to carefully consider the kind of inferences that particular training data are able to afford, especially in arenas where the potential clinical benefit is so large.
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Affiliation(s)
- Agnes Norbury
- Computational and Biological Learning Laboratory, Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
| | - Ben Seymour
- Computational and Biological Learning Laboratory, Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, 565-0871, Japan
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99
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Norbury A, Seymour B. Response heterogeneity: Challenges for personalised medicine and big data approaches in psychiatry and chronic pain. F1000Res 2018; 7:55. [PMID: 29527298 PMCID: PMC5820606 DOI: 10.12688/f1000research.13723.2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/28/2018] [Indexed: 12/28/2022] Open
Abstract
Response rates to available treatments for psychological and chronic pain disorders are poor, and there is a substantial burden of suffering and disability for patients, who often cycle through several rounds of ineffective treatment. As individuals presenting to the clinic with symptoms of these disorders are likely to be heterogeneous, there is considerable interest in the possibility that different constellations of signs could be used to identify subgroups of patients that might preferentially benefit from particular kinds of treatment. To this end, there has been a recent focus on the application of machine learning methods to attempt to identify sets of predictor variables (demographic, genetic, etc.) that could be used to target individuals towards treatments that are more likely to work for them in the first instance. Importantly, the training of such models generally relies on datasets where groups of individual predictor variables are labelled with a binary outcome category - usually 'responder' or 'non-responder' (to a particular treatment). However, as previously highlighted in other areas of medicine, there is a basic statistical problem in classifying individuals as 'responding' to a particular treatment on the basis of data from conventional randomized controlled trials. Specifically, insufficient information on the partition of variance components in individual symptom changes mean that it is inappropriate to consider data from the active treatment arm alone in this way. This may be particularly problematic in the case of psychiatric and chronic pain symptom data, where both within-subject variability and measurement error are likely to be high. Here, we outline some possible solutions to this problem in terms of dataset design and machine learning methodology, and conclude that it is important to carefully consider the kind of inferences that particular training data are able to afford, especially in arenas where the potential clinical benefit is so large.
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Affiliation(s)
- Agnes Norbury
- Computational and Biological Learning Laboratory, Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
| | - Ben Seymour
- Computational and Biological Learning Laboratory, Department of Engineering, University of Cambridge, Cambridge, CB2 1PZ, UK
- Center for Information and Neural Networks, National Institute of Information and Communications Technology, Osaka, 565-0871, Japan
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100
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Cortés J, González JA, Medina MN, Vogler M, Vilaró M, Elmore M, Senn SJ, Campbell M, Cobo E. Does evidence support the high expectations placed in precision medicine? A bibliographic review. F1000Res 2018; 7:30. [PMID: 31143439 DOI: 10.12688/f1000research.13490.4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/04/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Precision medicine is the Holy Grail of interventions that are tailored to a patient's individual characteristics. However, conventional clinical trials are designed to find differences in averages, and interpreting these differences depends on untestable assumptions. Although only an ideal, a constant effect of treatment would facilitate individual management. A direct consequence of a constant effect is that the variance of the outcome measure would be the same in the treated and control arms. We reviewed the literature to explore the similarity of these variances as a foundation for examining whether and how often precision medicine is definitively required. Methods: We reviewed parallel clinical trials with numerical primary endpoints published in 2004, 2007, 2010 and 2013. We collected the baseline and final standard deviations of the main outcome measure. We assessed homoscedasticity by comparing the variance of the primary endpoint between arms through the outcome variance ratio (treated to control group). Results: The review provided 208 articles with enough information to conduct the analysis. One out of five studies (n = 40, 19.2%) had statistically different variances between groups, implying a non-constant-effect. The adjusted point estimate of the mean outcome variance ratio (treated to control group) is 0.89 (95% CI 0.81 to 0.97). Conclusions: The mean variance ratio is significantly lower than 1 and the lower variance was found more often in the intervention group than in the control group, suggesting it is more usual for treated patients to be stable. This observed reduction in variance might also imply that there could be a subgroup of less ill patients who derive no benefit from treatment. This would require further study as to whether the treatment effect outweighs the side effects as well as the economic costs. We have shown that there are ways to analyze the apparently unobservable constant effect.
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Affiliation(s)
- Jordi Cortés
- Department of Statistics and Operations Research, Universitat Politècnica de Catalunya, Barcelona, 08034, Spain
| | - José Antonio González
- Department of Statistics and Operations Research, Universitat Politècnica de Catalunya, Barcelona, 08034, Spain
| | | | - Markus Vogler
- Department of Statistics, Ludwig-Maximilians-Universität München, München, 80539, Germany
| | - Marta Vilaró
- Fundació lliga per a la investigació i prevenció del càncer, Reus, 43201, Spain
| | - Matt Elmore
- Department of Statistics and Operations Research, Universitat Politècnica de Catalunya, Barcelona, 08034, Spain
| | - Stephen John Senn
- Competence Center for Methodology and Statistics, Luxembourg Institute of Health, Strassen, 1445, Luxembourg
| | - Michael Campbell
- School of Health and Related Research, University of Sheffield, Sheffield, S1 4DA, UK
| | - Erik Cobo
- Department of Statistics and Operations Research, Universitat Politècnica de Catalunya, Barcelona, 08034, Spain
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