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Gaudry S, Messika J, Ricard JD, Guillo S, Pasquet B, Dubief E, Boukertouta T, Dreyfuss D, Tubach F. Patient-important outcomes in randomized controlled trials in critically ill patients: a systematic review. Ann Intensive Care 2017; 7:28. [PMID: 28271450 PMCID: PMC5340787 DOI: 10.1186/s13613-017-0243-z] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 02/09/2017] [Indexed: 12/18/2022] Open
Abstract
Background Intensivists’ clinical decision making pursues two main goals for patients: to decrease mortality and to improve quality of life and functional status in survivors. Patient-important outcomes are gaining wide acceptance in most fields of clinical research. We sought to systematically review how well patient-important outcomes are reported in published randomized controlled trials (RCTs) in critically ill patients. Methods Literature search was conducted to identify eligible trials indexed from January to December 2013. Articles were eligible if they reported an RCT involving critically ill adult patients. We excluded phase II, pilot and physiological crossover studies. We assessed study characteristics. All primary and secondary outcomes were collected, described and classified using six categories of outcomes including patient-important outcomes (involving mortality at any time on the one hand and quality of life, functional/cognitive/neurological outcomes assessed after ICU discharge on the other). Results Of the 716 articles retrieved in 2013, 112 RCTs met the inclusion criteria. Most common topics were mechanical ventilation (27%), sepsis (19%) and nutrition (17%). Among the 112 primary outcomes, 27 (24%) were patient-important outcomes (mainly mortality, 21/27) but only six (5%) were patient-important outcomes besides mortality assessed after ICU discharge (functional disability = 4; quality of life = 2). Among the 598 secondary outcomes, 133 (22%) were patient-important outcomes (mainly mortality, 92/133) but only 41 (7%) were patient-important outcomes besides mortality assessed after ICU discharge (quality of life = 20, functional disability = 14; neurological/cognitive performance = 5; handicap = 1; post-traumatic stress = 1). Seventy-three RCTs (65%) reported at least one patient-important outcome but only 11 (10%) reported at least one patient-important outcome besides mortality assessed after ICU discharge. Conclusion Patient-important outcomes are rarely primary outcomes in RCTs in critically ill patients published in 2013. Among them, mortality accounted for the majority. We promote the use of patient-important outcomes in critical care trials. Electronic supplementary material The online version of this article (doi:10.1186/s13613-017-0243-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Stéphane Gaudry
- Service de Réanimation Médico-Chirurgicale, Hôpital Louis Mourier, AP-HP, 178 rue des Renouillers, 92700, Colombes, France. .,ECEVE, UMRS 1123, Sorbonne Paris Cité, Univ Paris Diderot, Paris, France. .,ECEVE, U1123, CIC 1421, INSERM, Paris, France.
| | - Jonathan Messika
- Service de Réanimation Médico-Chirurgicale, Hôpital Louis Mourier, AP-HP, 178 rue des Renouillers, 92700, Colombes, France.,IAME, UMR 1137, INSERM, 75018, Paris, France.,IAME, UMR 1137, Sorbonne Paris Cité, Univ Paris Diderot, 75018, Paris, France
| | - Jean-Damien Ricard
- Service de Réanimation Médico-Chirurgicale, Hôpital Louis Mourier, AP-HP, 178 rue des Renouillers, 92700, Colombes, France.,IAME, UMR 1137, INSERM, 75018, Paris, France.,IAME, UMR 1137, Sorbonne Paris Cité, Univ Paris Diderot, 75018, Paris, France
| | - Sylvie Guillo
- ECEVE, UMRS 1123, Sorbonne Paris Cité, Univ Paris Diderot, Paris, France.,ECEVE, U1123, CIC 1421, INSERM, Paris, France.,Département de Biostatistiques, Santé Publique et Informatique Médicale, CIC 1421, Hôpital Pitié Salpétrière, AP-HP, Paris, France.,Unité de Recherche Clinique Paris Nord, Hôpital Bichat, AP-HP, Paris, France
| | - Blandine Pasquet
- Département de Biostatistiques, Santé Publique et Informatique Médicale, CIC 1421, Hôpital Pitié Salpétrière, AP-HP, Paris, France.,Unité de Recherche Clinique Paris Nord, Hôpital Bichat, AP-HP, Paris, France
| | - Emeline Dubief
- Service de Réanimation Médico-Chirurgicale, Hôpital Louis Mourier, AP-HP, 178 rue des Renouillers, 92700, Colombes, France
| | - Tanissia Boukertouta
- Service de Réanimation Médico-Chirurgicale, Hôpital Louis Mourier, AP-HP, 178 rue des Renouillers, 92700, Colombes, France
| | - Didier Dreyfuss
- Service de Réanimation Médico-Chirurgicale, Hôpital Louis Mourier, AP-HP, 178 rue des Renouillers, 92700, Colombes, France.,IAME, UMR 1137, INSERM, 75018, Paris, France.,IAME, UMR 1137, Sorbonne Paris Cité, Univ Paris Diderot, 75018, Paris, France
| | - Florence Tubach
- ECEVE, UMRS 1123, Sorbonne Paris Cité, Univ Paris Diderot, Paris, France.,ECEVE, U1123, CIC 1421, INSERM, Paris, France.,Département de Biostatistiques, Santé Publique et Informatique Médicale, CIC 1421, Hôpital Pitié Salpétrière, AP-HP, Paris, France.,Unité de Recherche Clinique Paris Nord, Hôpital Bichat, AP-HP, Paris, France.,Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
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Ciarleglio MM, Arendt CD. Sample size determination for a binary response in a superiority clinical trial using a hybrid classical and Bayesian procedure. Trials 2017; 18:83. [PMID: 28231813 PMCID: PMC5324236 DOI: 10.1186/s13063-017-1791-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 01/09/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND When designing studies that have a binary outcome as the primary endpoint, the hypothesized proportion of patients in each population experiencing the endpoint of interest (i.e., π 1,π 2) plays an important role in sample size and power calculations. Point estimates for π 1 and π 2 are often calculated using historical data. However, the uncertainty in these estimates is rarely addressed. METHODS This paper presents a hybrid classical and Bayesian procedure that formally integrates prior information on the distributions of π 1 and π 2 into the study's power calculation. Conditional expected power (CEP), which averages the traditional power curve using the prior distributions of π 1 and π 2 as the averaging weight conditional on the presence of a positive treatment effect (i.e., π 2>π 1), is used, and the sample size is found that equates the pre-specified frequentist power (1-β) and the conditional expected power of the trial. RESULTS Notional scenarios are evaluated to compare the probability of achieving a target value of power with a trial design based on traditional power and a design based on CEP. We show that if there is uncertainty in the study parameters and a distribution of plausible values for π 1 and π 2, the performance of the CEP design is more consistent and robust than traditional designs based on point estimates for the study parameters. Traditional sample size calculations based on point estimates for the hypothesized study parameters tend to underestimate the required sample size needed to account for the uncertainty in the parameters. The greatest marginal benefit of the proposed method is achieved when the uncertainty in the parameters is not large. CONCLUSIONS Through this procedure, we are able to formally integrate prior information on the uncertainty and variability of the study parameters into the design of the study while maintaining a frequentist framework for the final analysis. Solving for the sample size that is necessary to achieve a high level of CEP given the available prior information helps protect against misspecification of hypothesized treatment effect and provides a substantiated estimate that forms the basis for discussion about the study's feasibility during the design phase.
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Affiliation(s)
- Maria M Ciarleglio
- Department of Biostatistics, Yale University School of Public Health, 60 College Street, New Haven, 06510, CT, USA. .,Clinical Epidemiology Research Center, VA Cooperative Studies Program, 950 Campbell Avenue, Bldg 35A, West Haven, 06516, CT, USA.
| | - Christopher D Arendt
- Air Force Office of Scientific Research, 875 N Randolph Street, Arlington, 22203, VA, USA
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Ridgeon EE, Young PJ, Bellomo R, Mucchetti M, Lembo R, Landoni G. The Fragility Index in Multicenter Randomized Controlled Critical Care Trials*. Crit Care Med 2016; 44:1278-84. [DOI: 10.1097/ccm.0000000000001670] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Watzlawick R, Rind J, Sena ES, Brommer B, Zhang T, Kopp MA, Dirnagl U, Macleod MR, Howells DW, Schwab JM. Olfactory Ensheathing Cell Transplantation in Experimental Spinal Cord Injury: Effect size and Reporting Bias of 62 Experimental Treatments: A Systematic Review and Meta-Analysis. PLoS Biol 2016; 14:e1002468. [PMID: 27244556 PMCID: PMC4886956 DOI: 10.1371/journal.pbio.1002468] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 04/25/2016] [Indexed: 11/18/2022] Open
Abstract
Olfactory ensheathing cell (OEC) transplantation is a candidate cellular treatment approach for human spinal cord injury (SCI) due to their unique regenerative potential and autologous origin. The objective of this study was, through a meta-epidemiologic approach, (i) to assess the efficacy of OEC transplantation on locomotor recovery after traumatic experimental SCI and (ii) to estimate the likelihood of reporting bias and/or missing data. A study protocol was finalized before data collection. Embedded into a systematic review and meta-analysis, we conducted a literature research of databases including PubMed, EMBASE, and ISI Web of Science from 1949/01 to 2014/10 with no language restrictions, screened by two independent investigators. Studies were included if they assessed neurobehavioral improvement after traumatic experimental SCI, administrated no combined interventions, and reported the number of animals in the treatment and control group. Individual effect sizes were pooled using a random effects model. Details regarding the study design were extracted and impact of these on locomotor outcome was assessed by meta-regression. Missing data (reporting bias) was determined by Egger regression and Funnel-plotting. The primary study outcome assessed was improvement in locomotor function at the final time point of measurement. We included 49 studies (62 experiments, 1,164 animals) in the final analysis. The overall improvement in locomotor function after OEC transplantation, measured using the Basso, Beattie, and Bresnahan (BBB) score, was 20.3% (95% CI 17.8–29.5). One missing study was imputed by trim and fill analysis, suggesting only slight publication bias and reducing the overall effect to a 19.2% improvement of locomotor activity. Dose-response ratio supports neurobiological plausibility. Studies were assessed using a 9-point item quality score, resulting in a median score of 5 (interquartile range [IQR] 3–5). In conclusion, OEC transplantation exerts considerable beneficial effects on neurobehavioral recovery after traumatic experimental SCI. Publication bias was minimal and affirms the translational potential of efficacy, but safety cannot be adequately assessed. The data justify OECs as a cellular substrate to develop and optimize minimally invasive and safe cellular transplantation paradigms for the lesioned spinal cord embedded into state-of-the-art Phase I/II clinical trial design studies for human SCI. This meta-analysis study examines the effects of transplanting olfactory ensheathing cells in rodents with experimental spinal cord injury, finding evidence for significant recovery and identifying aspects of the procedure that influence the effect size. Spinal cord injury converts into a debilitating disease affecting millions of chronic patients worldwide. Despite increased molecular knowledge over the last decades, no causal pharmacological or cellular therapy has proven effective so far. Due to their unique regenerative capabilities and their autologous origin, olfactory ensheathing cells (OECs) constitute an appealing candidate for topical cell transplantation. In contrast to few and heterogeneous experimental reports of OEC transplantation after spinal cord injury in humans, a considerable number of preclinical studies have been conducted applying OEC transplantation in rodent models. We set out to conduct a systematic review and meta-analysis to assess preclinical efficacy of OEC transplantation. We detected a significant overall increase of functional neurological recovery in animals after OEC transplantation compared to the control group. This effect was not distorted by publication bias. We identified several specific hallmarks of the cell transplantation procedure that determine the effect size of the transplantation. Our findings delineate conditions for optimized OEC transplantation into lesioned spinal cords and its relevance for effective translation to human trials.
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Affiliation(s)
- Ralf Watzlawick
- Department of Neurology and Experimental Neurology, Charité Campus Mitte, Clinical and Experimental Spinal Cord Injury Research Laboratory (Neuroparaplegiology), Charité–Universitätsmedizin Berlin, Berlin, Germany
- Department of Neurosurgery, University Medical Center Freiburg, Freiburg, Germany
| | - Julian Rind
- Department of Neurology and Experimental Neurology, Charité Campus Mitte, Clinical and Experimental Spinal Cord Injury Research Laboratory (Neuroparaplegiology), Charité–Universitätsmedizin Berlin, Berlin, Germany
| | - Emily S. Sena
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
- Stroke Division, Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia
| | - Benedikt Brommer
- Department of Neurology and Experimental Neurology, Charité Campus Mitte, Clinical and Experimental Spinal Cord Injury Research Laboratory (Neuroparaplegiology), Charité–Universitätsmedizin Berlin, Berlin, Germany
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, United States of America
| | - Tian Zhang
- Center for Stroke Research Berlin, Charité–Universitätsmedizin, Berlin, Germany
| | - Marcel A. Kopp
- Center for Stroke Research Berlin, Charité–Universitätsmedizin, Berlin, Germany
| | - Ulrich Dirnagl
- Center for Stroke Research Berlin, Charité–Universitätsmedizin, Berlin, Germany
- German Center for Neurodegenerative Diseases (DZNE) Berlin site, Berlin, Germany
| | - Malcolm R. Macleod
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - David W. Howells
- Stroke Division, Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia
- University of Tasmania, School of Medicine, Faculty of Health, Medical Sciences Precinct, Hobart, Tasmania, Australia
| | - Jan M. Schwab
- Department of Neurology and Experimental Neurology, Charité Campus Mitte, Clinical and Experimental Spinal Cord Injury Research Laboratory (Neuroparaplegiology), Charité–Universitätsmedizin Berlin, Berlin, Germany
- Department of Neurology, Spinal Cord Injury Division, The Neurological Institute, The Ohio State University, Wexner Medical Center, Columbus, United States of America
- Department of Neuroscience and Center for Brain and Spinal Cord Repair, Department of Physical Medicine and Rehabilitation, The Neurological Institute, The Ohio State University, Wexner Medical Center, Columbus, United States of America
- * E-mail:
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Aberegg S. Challenging orthodoxy in critical care trial design: physiological responsiveness. ANNALS OF TRANSLATIONAL MEDICINE 2016; 4:147. [PMID: 27162797 DOI: 10.21037/atm.2016.03.45] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Pisano A, Landoni G, Lomivorotov V, Comis M, Gazivoda G, Conte M, Hajjar L, Finco G, Jovic M, Mucchetti M, Kunstýř J, Paternoster G, Likhvantsev V, Ruggeri L, Ma J, Alvaro G, Bukamal N, Borghi G, Pasyuga V, Cabrini L, Greco M, Guarracino F, Lembo R, Lobreglio R, Monaco F, Montisci A, Pala G, Pasin L, Pieri M, Santini F, Silvetti S, Zambon M, Baiardo Redaelli M, Castella A, De Vuono G, Lucchetta L, Zangrillo A, Bellomo R. Worldwide Opinion on Multicenter Randomized Interventions Showing Mortality Reduction in Critically Ill Patients: A Democracy-Based Medicine Approach. J Cardiothorac Vasc Anesth 2016; 30:1386-95. [PMID: 27499346 DOI: 10.1053/j.jvca.2016.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Indexed: 11/11/2022]
Abstract
OBJECTIVES Democracy-based medicine is a combination of evidence-based medicine (systematic review), expert assessment, and worldwide voting by physicians to express their opinions and self-reported practice via the Internet. The authors applied democracy-based medicine to key trials in critical care medicine. DESIGN AND SETTING A systematic review of literature followed by web-based voting on findings of a consensus conference. PARTICIPANTS A total of 555 clinicians from 61 countries. INTERVENTIONS The authors performed a systematic literature review (via searching MEDLINE/PubMed, Scopus, and Embase) and selected all multicenter randomized clinical trials in critical care that reported a significant effect on survival and were endorsed by expert clinicians. Then they solicited voting and self-reported practice on such evidence via an interactive Internet questionnaire. Relationships among trial sample size, design, and respondents' agreement were investigated. The gap between agreement and use/avoidance and the influence of country origin on physicians' approach to interventions also were investigated. MEASUREMENTS AND MAIN RESULTS According to 24 multicenter randomized controlled trials, 15 interventions affecting mortality were identified. Wide variabilities in both the level of agreement and reported practice among different interventions and countries were found. Moreover, agreement and reported practice often did not coincide. Finally, a positive correlation among agreement, trial sample size, and number of included centers was found. On the contrary, trial design did not influence clinicians' agreement. CONCLUSIONS Physicians' clinical practice and agreement with the literature vary among different interventions and countries. The role of these interventions in affecting survival should be further investigated to reduce both the gap between evidence and clinical practice and transnational differences.
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Affiliation(s)
- Antonio Pisano
- Division of Cardiac Anesthesia and Intensive Care, AORN "Dei Colli", Monaldi Hospital, Naples, Italy
| | - Giovanni Landoni
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy; Vita-Salute San Raffaele University, Milan, Italy.
| | | | - Marco Comis
- Cardiac and Vascular Department, Mauriziano Hospital, Turin, Italy
| | - Gordana Gazivoda
- Institute of Cardiovascular Diseases ׳Dedinje׳, Belgrade, Serbia
| | - Massimiliano Conte
- Department of Anesthesia and Intensive Care, Mater Dei Hospital, Bari, Italy
| | - Ludhmila Hajjar
- Intensive Care Unit, Universidade de Sao Paulo, Sao Paulo, Brazil
| | - Gabriele Finco
- Department of Medical Sciences "M. Aresu", University of Cagliari, Cagliari, Italy
| | - Miomir Jovic
- Institute of Cardiovascular Diseases ׳Dedinje׳, Belgrade, Serbia
| | - Marta Mucchetti
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Jan Kunstýř
- Department of Anesthesiology and Intensive Care, First Faculty of Medicine, Charles University in Prague, and General University Hospital in Prague, Prague, Czech Republic
| | - Gianluca Paternoster
- Cardiovascular Anaesthesia and Intensive Care, San Carlo Hospital, Potenza, Italy
| | | | - Laura Ruggeri
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Jun Ma
- Center for Anesthesiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Gabriele Alvaro
- Department of Anesthesia and Intensive Care, Azienda Ospedaliero-Universitaria "Mater Domini", Catanzaro, Italy
| | - Nazar Bukamal
- Mohammed Bin Khalifa Bin Sulman Al-Khalifa Cardiac Center, West Riffa, Bahrain
| | - Giovanni Borghi
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Vadim Pasyuga
- Cardiac Anesthesia and Intensive Care, Federal Centre for Cardiac Surgery, Astrakhan, Russia
| | - Luca Cabrini
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Massimiliano Greco
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Fabio Guarracino
- Cardiothoracic Department, University Hospital of Pisa, Pisa, Italy
| | - Rosalba Lembo
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Rosetta Lobreglio
- Cardiac Anesthesia and Intensive Care, San Giovanni Battista Hospital, University of Turin, Turin, Italy
| | - Fabrizio Monaco
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Andrea Montisci
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Giovanni Pala
- Cardioanaesthesia and Intensive Care, Civil Hospital "SS Annunziata", Sassari, Italy
| | - Laura Pasin
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Marina Pieri
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Santini
- Division of Cardiac Surgery, IRCCS S Martino, University Hospital, Genova, Italy
| | - Simona Silvetti
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Massimo Zambon
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | | | - Alberto Castella
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Giovanni De Vuono
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Luca Lucchetta
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Alberto Zangrillo
- Department of Anesthesia and Intensive Care, San Raffaele Scientific Institute, Milan, Italy
| | - Rinaldo Bellomo
- Faculty of Medicine, University of Melbourne, Melbourne, Australia
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Summers MJ, Chapple LAS, McClave SA, Deane AM. Event-rate and delta inflation when evaluating mortality as a primary outcome from randomized controlled trials of nutritional interventions during critical illness: a systematic review. Am J Clin Nutr 2016; 103:1083-90. [PMID: 26961931 DOI: 10.3945/ajcn.115.122200] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND There is a lack of high-quality evidence that proves that nutritional interventions during critical illness reduce mortality. OBJECTIVES We evaluated whether power calculations for randomized controlled trials (RCTs) of nutritional interventions that used mortality as the primary outcome were realistic, and whether overestimation was systematic in the studies identified to determine whether this was due to overestimates of event rate or delta. DESIGN A systematic review of the literature between 2005 and 2015 was performed to identify RCTs of nutritional interventions administered to critically ill adults that had mortality as the primary outcome. Predicted event rate (predicted mortality during the control), predicted mortality during intervention, predicted delta (predicted difference between mortality during the control and intervention), actual event rate (observed mortality during control), observed mortality during intervention, and actual delta (difference between observed mortality during the control and intervention) were recorded. The event-rate gap (predicted event rate minus observed event rate), the delta gap (predicted delta minus observed delta), and the predicted number needed to treat were calculated. Data are shown as median (range). RESULTS Fourteen articles were extracted, with power calculations provided for 10 studies. The predicted event rate was 29.9% (20.0–52.4%), and the predicted delta was 7.9% (3.0–20.0%). If the study hypothesis was proven correct then, on the basis of the power calculations, the number needed to treat would have been 12.7 (5.0–33.3) patients. The actual event rate was 25.3% (6.1–50.0%), the observed mortality during the intervention was 24.4% (6.3–39.7%), and the actual delta was 0.5% (−10.2–10.3%), such that the event-rate gap was 2.6% (−3.9–23.7%) and delta gap was 7.5% (3.2–25.2%). CONCLUSIONS Overestimates of delta occur frequently in RCTs of nutritional interventions in the critically ill that are powered to determine a mortality benefit. Delta inflation may explain the number of "negative" studies in this field of research.
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Abdulatif M, Mukhtar A, Obayah G. Pitfalls in reporting sample size calculation in randomized controlled trials published in leading anaesthesia journals: a systematic review. Br J Anaesth 2015; 115:699-707. [DOI: 10.1093/bja/aev166] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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Ciarleglio MM, Arendt CD, Makuch RW, Peduzzi PN. Selection of the treatment effect for sample size determination in a superiority clinical trial using a hybrid classical and Bayesian procedure. Contemp Clin Trials 2015; 41:160-71. [PMID: 25583273 DOI: 10.1016/j.cct.2015.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 12/27/2014] [Accepted: 01/02/2015] [Indexed: 11/19/2022]
Abstract
Specification of the treatment effect that a clinical trial is designed to detect (θA) plays a critical role in sample size and power calculations. However, no formal method exists for using prior information to guide the choice of θA. This paper presents a hybrid classical and Bayesian procedure for choosing an estimate of the treatment effect to be detected in a clinical trial that formally integrates prior information into this aspect of trial design. The value of θA is found that equates the pre-specified frequentist power and the conditional expected power of the trial. The conditional expected power averages the traditional frequentist power curve using the conditional prior distribution of the true unknown treatment effect θ as the averaging weight. The Bayesian prior distribution summarizes current knowledge of both the magnitude of the treatment effect and the strength of the prior information through the assumed spread of the distribution. By using a hybrid classical and Bayesian approach, we are able to formally integrate prior information on the uncertainty and variability of the treatment effect into the design of the study, mitigating the risk that the power calculation will be overly optimistic while maintaining a frequentist framework for the final analysis. The value of θA found using this method may be written as a function of the prior mean μ0 and standard deviation τ0, with a unique relationship for a given ratio of μ0/τ0. Results are presented for Normal, Uniform, and Gamma priors for θ.
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Affiliation(s)
- Maria M Ciarleglio
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, United States.
| | | | - Robert W Makuch
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, United States.
| | - Peter N Peduzzi
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, United States.
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Golfam M, Beall R, Brehaut J, Saeed S, Relton C, Ashbury FD, Little J. Comparing alternative design options for chronic disease prevention interventions. Eur J Clin Invest 2015; 45:87-99. [PMID: 25388015 DOI: 10.1111/eci.12371] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 11/01/2014] [Indexed: 12/14/2022]
Abstract
BACKGROUND While the randomized clinical trial is considered to provide the highest level of evidence in clinical medicine, its superiority to other study designs in the context of prevention studies is debated. The purpose of this review was (i) to gather evidence about challenges facing both randomized controlled trials and observational designs for the conduct of population-based chronic disease prevention interventions and (ii) to consider the suitability of recently proposed hybrid designs for population-based prevention intervention studies. METHODS Rapid review methods were employed for this study. Articles published within 2007-2012, were included if they: (i) discussed challenges or benefits related to any intervention study design, (ii) compared randomized controlled trials (RCT) and observational designs or (iii) introduced a new study design potentially applicable to population-based interventions. After initial screening, papers retained for inclusion were subjected to content analysis and synthesis. RESULTS A total of 35 included articles were reviewed and used for synthesis. Both RCTs and observational studies are subject to multiple challenges, the main being external and internal validity for RCTs and observational designs, respectively. Four new hybrid designs identified. CONCLUSION Although any high quality design can produce high level of evidence, multiple challenges with prevention intervention RCTs or observational studies identified. New hybrid designs that carry benefits of randomized and observational methods may be the road ahead for to assess the effects of population-based interventions.
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Affiliation(s)
- Mohammad Golfam
- Department of Epidemiology and Community Medicine, University of Ottawa, Ottawa, ON, Canada; Nuclear Medicine Residency Program, Department of Medicine, University of Ottawa, Ottawa, ON, Canada
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Forbes AB, Akram M, Pilcher D, Cooper J, Bellomo R. Cluster randomised crossover trials with binary data and unbalanced cluster sizes: application to studies of near-universal interventions in intensive care. Clin Trials 2014; 12:34-44. [PMID: 25475880 DOI: 10.1177/1740774514559610] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Cluster randomised crossover trials have been utilised in recent years in the health and social sciences. Methods for analysis have been proposed; however, for binary outcomes, these have received little assessment of their appropriateness. In addition, methods for determination of sample size are currently limited to balanced cluster sizes both between clusters and between periods within clusters. This article aims to extend this work to unbalanced situations and to evaluate the properties of a variety of methods for analysis of binary data, with a particular focus on the setting of potential trials of near-universal interventions in intensive care to reduce in-hospital mortality. METHODS We derive a formula for sample size estimation for unbalanced cluster sizes, and apply it to the intensive care setting to demonstrate the utility of the cluster crossover design. We conduct a numerical simulation of the design in the intensive care setting and for more general configurations, and we assess the performance of three cluster summary estimators and an individual-data estimator based on binomial-identity-link regression. RESULTS For settings similar to the intensive care scenario involving large cluster sizes and small intra-cluster correlations, the sample size formulae developed and analysis methods investigated are found to be appropriate, with the unweighted cluster summary method performing well relative to the more optimal but more complex inverse-variance weighted method. More generally, we find that the unweighted and cluster-size-weighted summary methods perform well, with the relative efficiency of each largely determined systematically from the study design parameters. Performance of individual-data regression is adequate with small cluster sizes but becomes inefficient for large, unbalanced cluster sizes. When outcome prevalences are 6% or less and the within-cluster-within-period correlation is 0.05 or larger, all methods display sub-nominal confidence interval coverage, with the less prevalent the outcome the worse the coverage. LIMITATIONS As with all simulation studies, conclusions are limited to the configurations studied. We confined attention to detecting intervention effects on an absolute risk scale using marginal models and did not explore properties of binary random effects models. CONCLUSION Cluster crossover designs with binary outcomes can be analysed using simple cluster summary methods, and sample size in unbalanced cluster size settings can be determined using relatively straightforward formulae. However, caution needs to be applied in situations with low prevalence outcomes and moderate to high intra-cluster correlations.
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Affiliation(s)
- Andrew B Forbes
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - Muhammad Akram
- School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
| | - David Pilcher
- Centre for Outcome and Resource Evaluation (CORE), Australian and New Zealand Intensive Care Society (ANZICS), Carlton, VIC, Australia Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Monash University, Melbourne, VIC, Australia
| | - Jamie Cooper
- Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Monash University, Melbourne, VIC, Australia
| | - Rinaldo Bellomo
- Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Monash University, Melbourne, VIC, Australia
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Harhay MO, Wagner J, Ratcliffe SJ, Bronheim RS, Gopal A, Green S, Cooney E, Mikkelsen ME, Kerlin MP, Small DS, Halpern SD. Outcomes and statistical power in adult critical care randomized trials. Am J Respir Crit Care Med 2014; 189:1469-78. [PMID: 24786714 DOI: 10.1164/rccm.201401-0056cp] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
RATIONALE Intensive care unit (ICU)-based randomized clinical trials (RCTs) among adult critically ill patients commonly fail to detect treatment benefits. OBJECTIVES Appraise the rates of success, outcomes used, statistical power, and design characteristics of published trials. METHODS One hundred forty-six ICU-based RCTs of diagnostic, therapeutic, or process/systems interventions published from January 2007 to May 2013 in 16 high-impact general or critical care journals were studied. MEASUREMENT AND MAIN RESULTS Of 146 RCTs, 54 (37%) were positive (i.e., the a priori hypothesis was found to be statistically significant). The most common primary outcomes were mortality (n = 40 trials), infection-related outcomes (n = 33), and ventilation-related outcomes (n = 30), with positive results found in 10, 58, and 43%, respectively. Statistical power was discussed in 135 RCTs (92%); 92 cited a rationale for their power parameters. Twenty trials failed to achieve at least 95% of their reported target sample size, including 11 that were stopped early due to insufficient accrual/logistical issues. Of 34 superiority RCTs comparing mortality between treatment arms, 13 (38%) accrued a sample size large enough to find an absolute mortality reduction of 10% or less. In 22 of these trials the observed control-arm mortality rate differed from the predicted rate by at least 7.5%. CONCLUSIONS ICU-based RCTs are commonly negative and powered to identify what appear to be unrealistic treatment effects, particularly when using mortality as the primary outcome. Additional concerns include a lack of standardized methods for assessing common outcomes, unclear justifications for statistical power calculations, insufficient patient accrual, and incorrect predictions of baseline event rates.
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Affiliation(s)
- Michael O Harhay
- 1 Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics
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Registration and design alterations of clinical trials in critical care: a cross-sectional observational study. Intensive Care Med 2014; 40:700-22. [PMID: 24737256 DOI: 10.1007/s00134-014-3250-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 02/15/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE In 2005 the International Committee of Medical Journal Editors issued a requirement that all randomized controlled trials (RCTs) be registered primarily to prevent selective reporting (publication bias). However, registries allow for alterations in study protocol. Changes occurring before (or after) study completion could invalidate the original study intent, leading to publication of misleading conclusions. In RCTs involving critically ill patients, these concerns may be particularly acute because mortality is high and conditions investigated are usually syndromes rather than specific diseases. This study was conducted to estimate the registration rate of RCTs in critical care; and, among registered RCTs, to determine timing of registration and whether sample size or primary outcome were altered. METHODS We searched the MEDLINE database for RCTs that began after or continued through July 2005. We determined whether each trial had been registered and, for registered trials, compared registry data to data in the published manuscript. RESULTS Approximately two-thirds (66%) of trials were registered. Of these, 66% of registrations occurred after enrolment had commenced. Overall, 6% (5/90) of trials appropriately registered a sample size which was unchanged from the interval between registration and publication, and only 12% (11/90) reported primary outcomes that were both appropriately registered and unchanged. CONCLUSIONS Non-registration, or registration after trial initiation, are common in RCTs of critically ill patients. Among registered trials important protocol changes are often made between trial commencement and publication. This study identifies and quantifies the extent of this serious-but correctable-problem for RCTs in critically ill patients.
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Huang DT, Angus DC, Barnato A, Gunn SR, Kellum JA, Stapleton DK, Weissfeld LA, Yealy DM, Peake SL, Delaney A, Bellomo R, Cameron P, Higgins A, Holdgate A, Howe B, Webb SA, Williams P, Osborn TM, Mouncey PR, Harrison DA, Harvey SE, Rowan KM. Harmonizing international trials of early goal-directed resuscitation for severe sepsis and septic shock: methodology of ProCESS, ARISE, and ProMISe. Intensive Care Med 2013; 39:1760-75. [PMID: 23958738 PMCID: PMC3864363 DOI: 10.1007/s00134-013-3024-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 07/09/2013] [Indexed: 01/20/2023]
Abstract
PURPOSE To describe and compare the design of three independent but collaborating multicenter trials of early goal-directed resuscitation for severe sepsis and septic shock. METHODS We reviewed the three current trials, one each in the USA (ProCESS: protocolized care for early septic shock), Australasia (ARISE: Australasian resuscitation in sepsis evaluation), and the UK (ProMISe: protocolised management in sepsis). We used the 2010 CONSORT (consolidated standards of reporting trials) statement and the 2008 CONSORT extension for trials assessing non-pharmacologic treatments to describe and compare the underlying rationale, commonalities, and differences. RESULTS All three trials conform to CONSORT guidelines, address the same fundamental questions, and share key design elements. Each trial is a patient-level, equal-randomized, parallel-group superiority trial that seeks to enroll emergency department patients with inclusion criteria that are consistent with the original early goal-directed therapy (EGDT) trial (suspected or confirmed infection, two or more systemic inflammatory response syndrome criteria, and refractory hypotension or elevated lactate), is powered to detect a 6–8 % absolute mortality reduction (hospital or 90-day), and uses trained teams to deliver EGDT. Design differences appear to primarily be driven by between-country variation in health care context. The main difference between the trials is the inclusion of a third, alternative resuscitation strategy arm in ProCESS. CONCLUSIONS Harmonization of study design and methods between severe sepsis trials is feasible and may facilitate pooling of data on completion of the trials.
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Quality of reporting of randomized controlled trials published in Intensive Care Medicine from 2001 to 2010. Intensive Care Med 2013; 39:1386-95. [PMID: 23743522 DOI: 10.1007/s00134-013-2947-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 04/21/2013] [Indexed: 10/26/2022]
Abstract
PURPOSE To evaluate the methodological quality of randomized controlled trials (RCTs) published in Intensive Care Medicine from 2001 to 2010, and to compare it with a previous review of RCTs published from 1975 to 2000. METHODS We assessed the quality of reporting of randomization, blinding and participant flow, both individually and combined within the Jadad scale, and compared them with findings from our previous review. For RCTs published from 2001 to 2010, we also evaluated the frequency of distorted finding presentation (spin) and inflated predicted treatment effect (delta inflation). RESULTS In the 221 RCTs from 2001 to 2010, the sample size was significantly larger than in the older series, and there was a higher proportion of studies with negative findings. Reporting of the rationale for sample size estimation and allocation concealment increased significantly, but reporting of other important individual methodological components did not change substantially compared with the previous period and remained low. Among RCTs from 2001 to 2010, a spin strategy was used in 69 of 111 RCTs with statistically negative results, while delta inflation was present in 7 of 11 RCTs evaluating survival as a primary outcome. Papers with higher Jadad scores were cited more often than the others. CONCLUSIONS Quality of reporting of RCTs published in Intensive Care Medicine has only partly improved over time, and spin and delta bias are of frequent occurrence. There is a need for stronger adherence to CONSORT recommendations, with special emphasis on accurate description of randomization and blindness, and correct reporting of statistically non-significant results.
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Ferguson ND, Scales DC, Pinto R, Wilcox ME, Cook DJ, Guyatt GH, Schünemann HJ, Marshall JC, Herridge MS, Meade MO. Integrating Mortality and Morbidity Outcomes. Am J Respir Crit Care Med 2013. [DOI: 10.1164/rccm.201206-1057oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Turner EL, Perel P, Clayton T, Edwards P, Hernández AV, Roberts I, Shakur H, Steyerberg EW. Covariate adjustment increased power in randomized controlled trials: an example in traumatic brain injury. J Clin Epidemiol 2012; 65:474-81. [PMID: 22169080 PMCID: PMC3589911 DOI: 10.1016/j.jclinepi.2011.08.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 07/05/2011] [Accepted: 08/10/2011] [Indexed: 11/29/2022]
Abstract
OBJECTIVE We aimed to determine to what extent covariate adjustment could affect power in a randomized controlled trial (RCT) of a heterogeneous population with traumatic brain injury (TBI). STUDY DESIGN AND SETTING We analyzed 14-day mortality in 9,497 participants in the Corticosteroid Randomization After Significant Head Injury (CRASH) RCT of corticosteroid vs. placebo. Adjustment was made using logistic regression for baseline covariates of two validated risk models derived from external data (International Mission on Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury [IMPACT]) and from the CRASH data. The relative sample size (RESS) measure, defined as the ratio of the sample size required by an adjusted analysis to attain the same power as the unadjusted reference analysis, was used to assess the impact of adjustment. RESULTS Corticosteroid was associated with higher mortality compared with placebo (odds ratio=1.25, 95% confidence interval=1.13-1.39). RESS of 0.79 and 0.73 were obtained by adjustment using the IMPACT and CRASH models, respectively, which, for example, implies an increase from 80% to 88% and 91% power, respectively. CONCLUSION Moderate gains in power may be obtained using covariate adjustment from logistic regression in heterogeneous conditions such as TBI. Although analyses of RCTs might consider covariate adjustment to improve power, we caution against this approach in the planning of RCTs.
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Affiliation(s)
- Elizabeth L Turner
- Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
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Understanding health economic analysis in critical care: insights from recent randomized controlled trials. Curr Opin Crit Care 2012; 17:504-9. [PMID: 21900769 DOI: 10.1097/mcc.0b013e32834a4bc1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW The article reviews the methods of health economic analysis (HEA) in clinical trials of critically ill patients. Emphasis is placed on the usefulness of HEA in the context of positive and 'no effect' studies, with recent examples. RECENT FINDINGS The need to control costs and promote effective spending in caring for the critically ill has garnered considerable attention due to the high cost of critical illness. Many clinical trials focus on short-term mortality, ignoring costs and quality of life, and fail to change clinical practice or promote efficient use of resources. Incorporating HEA into clinical trials is a possible solution. Such studies have shown some interventions, although expensive, provide good value, whereas others should be withdrawn from clinical practice. Incorporating HEA into randomized controlled trials (RCTs) requires careful attention to collect all relevant costs. Decision trees, modeling assumptions and methods for collecting costs and measuring outcomes should be planned and published beforehand to minimize bias. SUMMARY Costs and cost-effectiveness are potentially useful outcomes in RCTs of critically ill patients. Future RCTs should incorporate parallel HEA to provide both economic outcomes, which are important to the community, alongside patient-centered outcomes, which are important to individuals.
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Maharaj R. Vasopressors and the search for the optimal trial design. Contemp Clin Trials 2011; 32:924-30. [PMID: 21807122 DOI: 10.1016/j.cct.2011.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 05/13/2011] [Accepted: 07/14/2011] [Indexed: 11/28/2022]
Abstract
Despite several advances in the care of critically ill patients, sepsis and septic shock continue to carry the largest burden of mortality and morbidity. Trials comparing vasopressors in shock have been disappointing and several key issues in methodology may need to be explored. There has been substantial progress in evolving adaptive trial methodology, however these have seldom been translated to clinical trials. This paper discusses some of the issues relevant to critical illness. To illustrate the potential contribution of adaptive trials we discuss fixed sample size design including event and time to event studies. We then explore group sequential and adaptive trial design, enrichment strategies and sample size re-estimation. An attractive feature of responsive adaptive designs is the flexibility to deal with unanticipated treatment effect size. If the observed effect size is larger than expected, early stopping is permitted. If the effect size is smaller than expected, sample size recalculation would be a reasonable choice in the face of an underpowered study. This allows for optimal efficiency in trial design. Reservations about adaptive trial design centre on issues of validity, feasibility and integrity of the study and are discussed in this paper.
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Affiliation(s)
- Ritesh Maharaj
- Consultant Intensive Care Medicine, Department of Anaesthesia and Intensive Care Medicine, Kings College Hospital, London, SE5 9RS, UK.
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Roozenbeek B, Lingsma HF, Perel P, Edwards P, Roberts I, Murray GD, Maas AI, Steyerberg EW. The added value of ordinal analysis in clinical trials: an example in traumatic brain injury. Crit Care 2011; 15:R127. [PMID: 21586148 PMCID: PMC3218993 DOI: 10.1186/cc10240] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 03/02/2011] [Accepted: 05/17/2011] [Indexed: 11/27/2022] Open
Abstract
Introduction In clinical trials, ordinal outcome measures are often dichotomized into two categories. In traumatic brain injury (TBI) the 5-point Glasgow outcome scale (GOS) is collapsed into unfavourable versus favourable outcome. Simulation studies have shown that exploiting the ordinal nature of the GOS increases chances of detecting treatment effects. The objective of this study is to quantify the benefits of ordinal analysis in the real-life situation of a large TBI trial. Methods We used data from the CRASH trial that investigated the efficacy of corticosteroids in TBI patients (n = 9,554). We applied two techniques for ordinal analysis: proportional odds analysis and the sliding dichotomy approach, where the GOS is dichotomized at different cut-offs according to baseline prognostic risk. These approaches were compared to dichotomous analysis. The information density in each analysis was indicated by a Wald statistic. All analyses were adjusted for baseline characteristics. Results Dichotomous analysis of the six-month GOS showed a non-significant treatment effect (OR = 1.09, 95% CI 0.98 to 1.21, P = 0.096). Ordinal analysis with proportional odds regression or sliding dichotomy showed highly statistically significant treatment effects (OR 1.15, 95% CI 1.06 to 1.25, P = 0.0007 and 1.19, 95% CI 1.08 to 1.30, P = 0.0002), with 2.05-fold and 2.56-fold higher information density compared to the dichotomous approach respectively. Conclusions Analysis of the CRASH trial data confirmed that ordinal analysis of outcome substantially increases statistical power. We expect these results to hold for other fields of critical care medicine that use ordinal outcome measures and recommend that future trials adopt ordinal analyses. This will permit detection of smaller treatment effects.
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Affiliation(s)
- Bob Roozenbeek
- Department of Neurosurgery, Antwerp University Hospital, Wilrijkstraat 10, Edegem, Belgium.
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Curry N, Hopewell S, Dorée C, Hyde C, Brohi K, Stanworth S. The acute management of trauma hemorrhage: a systematic review of randomized controlled trials. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2011; 15:R92. [PMID: 21392371 PMCID: PMC3219356 DOI: 10.1186/cc10096] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 12/15/2010] [Accepted: 03/09/2011] [Indexed: 12/13/2022]
Abstract
Introduction Worldwide, trauma is a leading cause of death and disability. Haemorrhage is responsible for up to 40% of trauma deaths. Recent strategies to improve mortality rates have focused on optimal methods of early hemorrhage control and correction of coagulopathy. We undertook a systematic review of randomized controlled trials (RCT) which evaluated trauma patients with hemorrhagic shock within the first 24 hours of injury and appraised how the interventions affected three outcomes: bleeding and/or transfusion requirements; correction of trauma induced coagulopathy and mortality. Methods Comprehensive searches were performed of MEDLINE, EMBASE, CENTRAL (The Cochrane Library Issue 7, 2010), Current Controlled Trials, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform (ICTRP) and the National Health Service Blood and Transplant Systematic Review Initiative (NHSBT SRI) RCT Handsearch Database. Results A total of 35 RCTs were identified which evaluated a wide range of clinical interventions in trauma hemorrhage. Many of the included studies were of low methodological quality and participant numbers were small. Bleeding outcomes were reported in 32 studies; 7 reported significantly reduced transfusion use following a variety of clinical interventions, but this was not accompanied by improved survival. Minimal information was found on traumatic coagulopathy across the identified RCTs. Overall survival was improved in only three RCTs: two small studies and a large study evaluating the use of tranexamic acid. Conclusions Despite 35 RCTs there has been little improvement in outcomes over the last few decades. No clear correlation has been demonstrated between transfusion requirements and mortality. The global trauma community should consider a coordinated and strategic approach to conduct well designed studies with pragmatic endpoints.
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Affiliation(s)
- Nicola Curry
- NHS Blood and Transplant, Oxford Radcliffe Hospitals NHS Trust and University of Oxford, Headley Way, Oxford, OX3 9BQ, UK.
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Roozenbeek B, Lingsma HF, Steyerberg EW, Maas AIR. Underpowered trials in critical care medicine: how to deal with them? Crit Care 2010; 14:423. [PMID: 20553632 PMCID: PMC2911724 DOI: 10.1186/cc9021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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