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Salsbury JA, Oakley JE, Julious SA, Hampson LV. Assurance methods for designing a clinical trial with a delayed treatment effect. Stat Med 2024; 43:3595-3612. [PMID: 38881219 DOI: 10.1002/sim.10136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 03/30/2024] [Accepted: 05/29/2024] [Indexed: 06/18/2024]
Abstract
An assurance calculation is a Bayesian alternative to a power calculation. One may be performed to aid the planning of a clinical trial, specifically setting the sample size or to support decisions about whether or not to perform a study. Immuno-oncology is a rapidly evolving area in the development of anticancer drugs. A common phenomenon that arises in trials of such drugs is one of delayed treatment effects, that is, there is a delay in the separation of the survival curves. To calculate assurance for a trial in which a delayed treatment effect is likely to be present, uncertainty about key parameters needs to be considered. If uncertainty is not considered, the number of patients recruited may not be enough to ensure we have adequate statistical power to detect a clinically relevant treatment effect and the risk of an unsuccessful trial is increased. We present a new elicitation technique for when a delayed treatment effect is likely and show how to compute assurance using these elicited prior distributions. We provide an example to illustrate how this can be used in practice and develop open-source software to implement our methods. Our methodology has the potential to improve the success rate and efficiency of Phase III trials in immuno-oncology and for other treatments where a delayed treatment effect is expected to occur.
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Affiliation(s)
- James A Salsbury
- The School of Mathematics and Statistics, The University of Sheffield, Sheffield, UK
| | - Jeremy E Oakley
- The School of Mathematics and Statistics, The University of Sheffield, Sheffield, UK
| | - Steven A Julious
- The School of Health and Related Research, The University of Sheffield, Sheffield, UK
| | - Lisa V Hampson
- Advanced Methodology and Data Science, Novartis Pharma AG, Basel, Switzerland
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Zheng H, Jaki T, Wason JM. Bayesian sample size determination using commensurate priors to leverage preexperimental data. Biometrics 2023; 79:669-683. [PMID: 35253201 PMCID: PMC10952893 DOI: 10.1111/biom.13649] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 02/23/2022] [Indexed: 12/01/2022]
Abstract
This paper develops Bayesian sample size formulae for experiments comparing two groups, where relevant preexperimental information from multiple sources can be incorporated in a robust prior to support both the design and analysis. We use commensurate predictive priors for borrowing of information and further place Gamma mixture priors on the precisions to account for preliminary belief about the pairwise (in)commensurability between parameters that underpin the historical and new experiments. Averaged over the probability space of the new experimental data, appropriate sample sizes are found according to criteria that control certain aspects of the posterior distribution, such as the coverage probability or length of a defined density region. Our Bayesian methodology can be applied to circumstances that compare two normal means, proportions, or event times. When nuisance parameters (such as variance) in the new experiment are unknown, a prior distribution can further be specified based on preexperimental data. Exact solutions are available based on most of the criteria considered for Bayesian sample size determination, while a search procedure is described in cases for which there are no closed-form expressions. We illustrate the application of our sample size formulae in the design of clinical trials, where pretrial information is available to be leveraged. Hypothetical data examples, motivated by a rare-disease trial with an elicited expert prior opinion, and a comprehensive performance evaluation of the proposed methodology are presented.
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Affiliation(s)
- Haiyan Zheng
- MRC Biostatistics UnitUniversity of CambridgeCambridgeUK
- Population Health Sciences InstituteNewcastle UniversityNewcastle upon TyneUK
| | - Thomas Jaki
- MRC Biostatistics UnitUniversity of CambridgeCambridgeUK
- Department of Mathematics and StatisticsLancaster UniversityLancasterUK
| | - James M.S. Wason
- Population Health Sciences InstituteNewcastle UniversityNewcastle upon TyneUK
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3
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Wang Y, Travis J, Gajewski B. Bayesian adaptive design for pediatric clinical trials incorporating a community of prior beliefs. BMC Med Res Methodol 2022; 22:118. [PMID: 35448963 PMCID: PMC9027907 DOI: 10.1186/s12874-022-01569-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 03/09/2022] [Indexed: 11/21/2022] Open
Abstract
Background Pediatric population presents several barriers for clinical trial design and analysis, including ethical constraints on the sample size and slow accrual rate. Bayesian adaptive design methods could be considered to address these challenges in pediatric clinical trials. Methods We developed an innovative Bayesian adaptive design method and demonstrated the approach as a re-design of a published phase III pediatric trial. The innovative design used early success criteria based on skeptical prior and early futility criteria based on enthusiastic prior extrapolated from a historical adult trial, and the early and late stopping boundaries were calibrated to ensure a one-sided type I error of 2.5%. We also constructed several alternative designs which incorporated only one type of prior belief and the same stopping boundaries. To identify a preferred design, we compared operating characteristics including power, expected trial size and trial duration for all the candidate adaptive designs via simulation when performing an increasing number of equally spaced interim analyses. Results When performing an increasing number of equally spaced interim analyses, the innovative Bayesian adaptive trial design incorporating both skeptical and enthusiastic priors at both interim and final analyses outperforms alternative designs which only consider one type of prior belief, because it allows more reduction in sample size and trial duration while still offering good trial design properties including controlled type I error rate and sufficient power. Conclusions Designing a Bayesian adaptive pediatric trial with both skeptical and enthusiastic priors can be an efficient and robust approach for early trial stopping, thus potentially saving time and money for trial conduction. Supplementary Information The online version contains supplementary material available at 10.1186/s12874-022-01569-x.
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Affiliation(s)
- Yu Wang
- Department of Biostatistics & Data Science, University of Kansas Medical Center, Robinson 5028, 3901 Rainbow Blvd., Kansas City, KS, 66160, USA.
| | - James Travis
- Division of Biometrics II, Office of Biostatistics, Office of Translational Sciences, Center of Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, MD, 20993, USA
| | - Byron Gajewski
- Department of Biostatistics & Data Science, University of Kansas Medical Center, Robinson 5028, 3901 Rainbow Blvd., Kansas City, KS, 66160, USA
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4
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Lan J, Plint AC, Dalziel SR, Klassen TP, Offringa M, Heath A. Remote, real-time expert elicitation to determine the prior probability distribution for Bayesian sample size determination in international randomised controlled trials: Bronchiolitis in Infants Placebo Versus Epinephrine and Dexamethasone (BIPED) study. Trials 2022; 23:279. [PMID: 35410375 PMCID: PMC8996198 DOI: 10.1186/s13063-022-06240-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 03/28/2022] [Indexed: 11/10/2022] Open
Abstract
Background Bayesian methods are increasing in popularity in clinical research. The design of Bayesian clinical trials requires a prior distribution, which can be elicited from experts. In diseases with international differences in management, the elicitation exercise should recruit internationally, making a face-to-face elicitation session expensive and more logistically challenging. Thus, we used a remote, real-time elicitation exercise to construct prior distributions. These elicited distributions were then used to determine the sample size of the Bronchiolitis in Infants with Placebo Versus Epinephrine and Dexamethasone (BIPED) study, an international randomised controlled trial in the Pediatric Emergency Research Network (PERN). The BIPED study aims to determine whether the combination of epinephrine and dexamethasone, compared to placebo, is effective in reducing hospital admission for infants presenting with bronchiolitis to the emergency department. Methods We developed a Web-based tool to support the elicitation of the probability of hospitalisation for infants with bronchiolitis. Experts participated in online workshops to specify their individual prior distributions, which were aggregated using the equal-weighted linear pooling method. Experts were then invited to provide their comments on the aggregated distribution. The average length criterion determined the BIPED sample size. Results Fifteen paediatric emergency medicine clinicians from Canada, the USA, Australia and New Zealand participated in three workshops to provide their elicited prior distributions. The mean elicited probability of admission for infants with bronchiolitis was slightly lower for those receiving epinephrine and dexamethasone compared to supportive care in the aggregate distribution. There were substantial differences in the individual beliefs but limited differences between North America and Australasia. From this aggregate distribution, a sample size of 410 patients per arm results in an average 95% credible interval length of less than 9% and a relative predictive power of 90%. Conclusion Remote, real-time expert elicitation is a feasible, useful and practical tool to determine a prior distribution for international randomised controlled trials. Bayesian methods can then determine the trial sample size using these elicited prior distributions. The ease and low cost of remote expert elicitation mean that this approach is suitable for future international randomised controlled trials. Trial registration ClinicalTrials.govNCT03567473 Supplementary Information The online version contains supplementary material available at 10.1186/s13063-022-06240-w.
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Zheng H, Jaki T, Wason JMS. Bayesian sample size determination using commensurate priors to leverage pre-experimental data. Biometrics 2022; 79:669-683. [PMID: 38523700 PMCID: PMC7614678 DOI: 10.1111/j.1541-0420.2005.00454.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
This paper develops Bayesian sample size formulae for experiments comparing two groups, where relevant pre-experimental information from multiple sources can be incorporated in a robust prior to support both the design and analysis. We use commensurate predictive priors for borrowing of information, and further place Gamma mixture priors on the precisions to account for preliminary belief about the pairwise (in)commensurability between parameters that underpin the historical and new experiments. Averaged over the probability space of the new experimental data, appropriate sample sizes are found according to criteria that control certain aspects of the posterior distribution, such as the coverage probability or length of a defined density region. Our Bayesian methodology can be applied to circumstances that compare two normal means, proportions or event times. When nuisance parameters (such as variance) in the new experiment are unknown, a prior distribution can further be specified based on pre-experimental data. Exact solutions are available based on most of the criteria considered for Bayesian sample size determination, while a search procedure is described in cases for which there are no closed-form expressions. We illustrate the application of our sample size formulae in the design of clinical trials, where pre-trial information is available to be leveraged. Hypothetical data examples, motivated by a rare-disease trial with elicited expert prior opinion, and a comprehensive performance evaluation of the proposed methodology are presented.
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Affiliation(s)
- Haiyan Zheng
- MRC Biostatistics Unit, University of Cambridge, U.K
- Population Health Sciences Institute, Newcastle University, U.K
| | - Thomas Jaki
- MRC Biostatistics Unit, University of Cambridge, U.K
- Department of Mathematics and Statistics, Lancaster University, U.K
| | - James M S Wason
- Population Health Sciences Institute, Newcastle University, U.K
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Partington G, Cro S, Mason A, Phillips R, Cornelius V. Design and analysis features used in small population and rare disease trials: A targeted review. J Clin Epidemiol 2021; 144:93-101. [PMID: 34910979 DOI: 10.1016/j.jclinepi.2021.12.009] [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: 09/16/2021] [Revised: 11/24/2021] [Accepted: 12/07/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVE Frequentist trials in Rare disease/small population trials often require unfeasibly large sample size to detect minimum clinically important differences. A targeted review was performed investigating what design and analysis methods these trials use when facing restricted recruitment. STUDY DESIGN AND SETTING Targeted Review searching EMBASE and MEDLINE for Phase II-IV RCTs reporting 'rare' disease or 'small population' within title or abstract, since 2009. RESULTS A total of 6,128 articles were screened with 64 trials eligible (4 Bayesian, 60 frequentist trials). Frequentists trials had planned power ranging 72-90% (median: 80%) but reported recruiting a mean of 6.6% below the planned sample size (n=38) [median 0%, IQR (-5%, 5%)], most used standard type 1 error (52 used 5% and 1 used 1%), and the average standardised effect was high (0.7) with 50% missing their assumed level. Of the 4 Bayesian trials, 3 used informed priors, 2 and 1 trials performed sensitivity analysis for the impact of priors on design and analysis respectively. Historical data, expert consensus, or both were used to construct informative priors. Bayesian trials required 30%-2400% less participants than using frequentist frameworks. CONCLUSION Bayesian trials required lower sample size through use of informative priors. Most frequentists didn't achieve their target sample size. Bayesian methods offer promising solutions for such trials but are underutilised.
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Affiliation(s)
- Giles Partington
- Imperial Clinical Trials Unit, Imperial College London, 1st Floor Stadium House, 68 Wood Lane, London, United Kingdom W12 7RH.
| | - Suzie Cro
- Imperial Clinical Trials Unit, Imperial College London, 1st Floor Stadium House, 68 Wood Lane, London, United Kingdom W12 7RH
| | - Alexina Mason
- Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, Keppel Street, London, United Kingdom WC1E 7HT
| | - Rachel Phillips
- Imperial Clinical Trials Unit, Imperial College London, 1st Floor Stadium House, 68 Wood Lane, London, United Kingdom W12 7RH
| | - Victoria Cornelius
- Imperial Clinical Trials Unit, Imperial College London, 1st Floor Stadium House, 68 Wood Lane, London, United Kingdom W12 7RH
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Ramanan AV, Guly CM, Keller SY, Schlichting DE, de Bono S, Liao R, Quartier P. Clinical effectiveness and safety of baricitinib for the treatment of juvenile idiopathic arthritis-associated uveitis or chronic anterior antinuclear antibody-positive uveitis: study protocol for an open-label, adalimumab active-controlled phase 3 clinical trial (JUVE-BRIGHT). Trials 2021; 22:689. [PMID: 34627340 PMCID: PMC8502273 DOI: 10.1186/s13063-021-05651-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 09/23/2021] [Indexed: 11/12/2022] Open
Abstract
Background Juvenile idiopathic arthritis (JIA) is the most common pediatric rheumatic disease and the most common systemic disorder associated with uveitis in childhood. Uveitis is more common in JIA patients who are antinuclear antibody (ANA)-positive, have an early-onset disease, and have oligoarticular arthritis. JIA-associated uveitis (JIA-uveitis) is typically anterior, chronic, bilateral, nongranulomatous, and asymptomatic. Visual outcomes in JIA-uveitis have improved with current screening and treatment options; however, many patients fail to respond or do not achieve long-lasting remission. Baricitinib, an oral selective Janus kinase (JAK)1 and 2 inhibitor, may impact key cytokines implicated in the pathogenesis of JIA-uveitis or ANA-positive uveitis, representing a potential novel treatment option for disease management. Methods The multicenter, phase 3 trial will be conducted using an open-label Bayesian design. The study will enroll at least 20 and up to 40 patients aged 2 to <18 years with active JIA-uveitis or chronic ANA-positive uveitis without systemic features. At least 20 patients who have had an inadequate response or intolerance to methotrexate (MTX-IR), but not biologic disease-modifying antirheumatic drugs (bDMARDs), will be randomized (1:1) to open-label baricitinib or adalimumab. Approximately 20 additional patients who are MTX-IR or bDMARD inadequate responders will receive baricitinib treatment. Patients will be treated with once daily oral baricitinib at a fixed dose by age group (4 mg for patients aged ≥6 to <18 years and 2 mg for patients <6 years) or adalimumab (20 mg for patients weighing <30 kg and 40 mg for patients ≥30 kg) as a subcutaneous injection every 2 weeks. Treatment with stable background conventional synthetic DMARDs, low-dose corticosteroids, and/or nonsteroidal anti-inflammatory drugs is allowed. The primary endpoint is the proportion of patients with response at week 24. Patients may continue treatment for up to 5 years. Discussion This is the first pediatric clinical trial to assess the clinical effectiveness and safety of a JAK inhibitor in JIA-uveitis or chronic ANA-positive uveitis. A novel Bayesian design is used to assess the efficacy of baricitinib, including an adalimumab reference arm, in this small patient population with unmet medical need. Trial registration EudraCT 2019-000119-10. Registered on January 4, 2019; NCT04088409. Registered on September 12, 2019
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Affiliation(s)
- Athimalaipet V Ramanan
- Translational Health Sciences, University of Bristol, Bristol, UK. .,Department of Paediatric Rheumatology, University Hospitals Bristol NHS Foundation Trust, Bristol Royal Hospital for Children, Upper Maudlin Street, Bristol, BS2 8BJ, UK.
| | - Catherine M Guly
- Bristol Eye Hospital, University Hospitals Bristol NHS Foundation Trust, Bristol, UK
| | | | | | | | - Ran Liao
- Eli Lilly and Company, Indianapolis, IN, USA
| | - Pierre Quartier
- Pediatric Immunology-Hematology and Rheumatology Unit, RAISE reference centre for rare diseases, Necker-Enfants Malades University Hospital, Assistance Publique-Hopitaux de Paris, IMAGINE Institute, Université de Paris, Paris, France
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Desai Y, Jaki T, Beresford MW, Burnett T, Eleftheriou D, Jacobe H, Leone V, Li S, Mozgunov P, Ramanan AV, Torok KS, Anderson ME, Anton J, Avcin T, Felton J, Foeldvari I, Laguda B, McErlane F, Shaw L, Zulian F, Pain CE. Prior elicitation of the efficacy and tolerability of Methotrexate and Mycophenolate Mofetil in Juvenile Localised Scleroderma. AMRC OPEN RESEARCH 2021; 3:20. [PMID: 38708070 PMCID: PMC11064983 DOI: 10.12688/amrcopenres.13008.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 07/30/2021] [Indexed: 05/07/2024]
Abstract
Background Evidence is lacking for safe and effective treatments for juvenile localised scleroderma (JLS). Methotrexate (MTX) is commonly used first line and mycophenolate mofetil (MMF) second line, despite a limited evidence base. A head to head trial of these two medications would provide data on relative efficacy and tolerability. However, a frequentist approach is difficult to deliver in JLS, because of the numbers needed to sufficiently power a trial. A Bayesian approach could be considered. Methods An international consensus meeting was convened including an elicitation exercise where opinion was sought on the relative efficacy and tolerability of MTX compared to MMF to produce prior distributions for a future Bayesian trial. Secondary aims were to achieve consensus agreement on critical aspects of a future trial. Results An international group of 12 clinical experts participated. Opinion suggested superior efficacy and tolerability of MMF compared to MTX; where most likely value of efficacy of MMF was 0.70 (95% confidence interval (CI) 0.34-0.90) and of MTX was 0.68 (95% CI 0.41-0.8). The most likely value of tolerability of MMF was 0.77 (95% CI 0.3-0.94) and of MTX was 0.62 (95% CI 0.32-0.84). The wider CI for MMF highlights that experts were less sure about relative efficacy and tolerability of MMF compared to MTX. Despite using a Bayesian approach, power calculations still produced a total sample size of 240 participants, reflecting the uncertainty amongst experts about the performance of MMF. Conclusions Key factors have been defined regarding the design of a future Bayesian approach clinical trial including elicitation of prior opinion of the efficacy and tolerability of MTX and MMF in JLS. Combining further efficacy data on MTX and MMF with prior opinion could potentially reduce the pre-trial uncertainty so that, when combined with smaller trial sample sizes a compelling evidence base is available.
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Affiliation(s)
- Yasin Desai
- MPS Research Unit, Department of Mathematics and Statistics, Lancaster University, Lancaster, LA1 4YF, UK
| | - Thomas Jaki
- MPS Research Unit, Department of Mathematics and Statistics, Lancaster University, Lancaster, LA1 4YF, UK
- MRC Biostatistics Unit, University of Cambridge, Cambridge, CB2 0SR, UK
| | - Michael W Beresford
- Department of Paediatric Rheumatology, Alder Hey Children’s NHS Foundation Trust, Liverpool, L12 2AP, UK
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, L69 3BX, UK
| | - Thomas Burnett
- MPS Research Unit, Department of Mathematics and Statistics, Lancaster University, Lancaster, LA1 4YF, UK
| | - Despina Eleftheriou
- University College London Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
- Department of Paediatric Rheumatology, Great Ormond St Hospital NHS Foundation Trust, London, WC1N 3JH, UK
| | - Heidi Jacobe
- UT Southwestern Medical Center, Dallas, Texas, TX 75390, USA
| | - Valentina Leone
- Paediatric Rheumatology Department, Leeds Children Hospital (Leeds Teaching Hospitals) and University of Leeds, Leeds, LS1 3EX, UK
| | - Suzanne Li
- Department of Pediatrics, Joseph M. Sanzari Children’s Hospital, Hackensack University Medical Center & Hackensack Meridian School of Medicine, Hackensack, New Jersey, NJ 07601, USA
| | - Pavel Mozgunov
- MPS Research Unit, Department of Mathematics and Statistics, Lancaster University, Lancaster, LA1 4YF, UK
| | - Athimalaipet V Ramanan
- University Hospitals Bristol NHS Foundation Trust & Translational Health Sciences, Bristol, BS1 3NU, UK
| | - Kathryn S Torok
- Division of Rheumatology, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Marina E Anderson
- Department of Rheumatology, Liverpool University Hospitals NHS Foundation Trust, Liverpool, L9 7AL, UK
- Lancaster Medical School, Lancaster University, Lancaster, LA1 4YF, UK
| | - Jordi Anton
- Pediatric Rheumatology, Hospital Sant Joan de Déu, University of Barcelona, Barcelona, Barcelona, 08007, UK
| | - Tadej Avcin
- Department of Allergology, Rheumatology and Clinical Immunology, University Children's Hospital, University Medical Centre, Ljubljana, 1000 Ljubljana, Slovenia
| | - Jessie Felton
- Department of Dermatology, Brighton and Sussex University Hospitals & Royal Alexandra Children’s Hospital, Brighton, BN2 1DH, UK
| | - Ivan Foeldvari
- Hamburg Centre for Pediatric and Adolescence Rheumatology, Hamburg, 22081 Hamburg, Germany
| | - Bisola Laguda
- Department of Paediatric Dermatology, Chelsea and Westminster Hospital, London, SW10 9NH, UK
| | - Flora McErlane
- Department of Paediatric Rheumatology, Great North Children's Hospital, Newcastle, NE1 4LP, UK
| | - Lindsay Shaw
- Department of Paediatric Rheumatology, Great Ormond St Hospital NHS Foundation Trust, London, WC1N 3JH, UK
- University Hospitals Bristol NHS Foundation Trust & Translational Health Sciences, Bristol, BS1 3NU, UK
| | - Francesco Zulian
- Department of Woman's and Child's Health, University of Padova, Padua, 35122 Padua, Italy
| | - Clare E Pain
- Department of Paediatric Rheumatology, Alder Hey Children’s NHS Foundation Trust, Liverpool, L12 2AP, UK
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Brogan PA, Arch B, Hickey H, Anton J, Iglesias E, Baildam E, Mahmood K, Cleary G, Moraitis E, Papadopoulou C, Beresford MW, Riley P, Demir S, Ozen S, Culeddu G, Hughes DA, Dolezalova P, Hampson LV, Whitehead J, Jayne D, Ruperto N, Tudur-Smith C, Eleftheriou D. Mycophenolate Mofetil Versus Cyclophosphamide for Remission Induction in Childhood Polyarteritis Nodosa: An Open-Label, Randomized, Bayesian Noninferiority Trial. Arthritis Rheumatol 2021; 73:1673-1682. [PMID: 33760371 DOI: 10.1002/art.41730] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 03/11/2021] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Cyclophosphamide (CYC) is used in clinical practice off-label for the induction of remission in childhood polyarteritis nodosa (PAN). Mycophenolate mofetil (MMF) might offer a less toxic alternative. This study was undertaken to explore the relative effectiveness of CYC and MMF treatment in a randomized controlled trial (RCT). METHODS This was an international, open-label, Bayesian RCT to investigate the relative effectiveness of CYC and MMF for remission induction in childhood PAN. Eleven patients with newly diagnosed childhood PAN were randomized (1:1) to receive MMF or intravenous CYC; all patients received the same glucocorticoid regimen. The primary end point was remission within 6 months while compliant with glucocorticoid taper. Bayesian distributions for remission rates were established a priori for MMF and CYC by experienced clinicians and updated to posterior distributions on trial completion. RESULTS Baseline disease activity and features were similar between the 2 treatment groups. The primary end point was met in 4 of 6 patients (67%) in the MMF group and 4 of 5 patients (80%) in the CYC group. Time to remission was shorter in the MMF group compared to the CYC group (median 7.1 weeks versus 17.6 weeks). No relapses occurred in either group within 18 months. Two serious infections were found to be likely linked to MMF treatment. Physical and psychosocial quality-of-life scores were superior in the MMF group compared to the CYC group at 6 months and 18 months. Combining the prior expert opinion with results from the present study provided posterior estimates of remission of 71% for MMF (90% credibility interval [90% CrI] 51, 83) and 75% for CYC (90% CrI 57, 86). CONCLUSION The present results, taken together with prior opinion, indicate that rates of remission induction in childhood PAN are similar with MMF treatment and CYC treatment, and MMF treatment might be associated with better health-related quality of life than CYC treatment.
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Affiliation(s)
- Paul A Brogan
- University College London Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | | | | | | | - Eileen Baildam
- Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - Kamran Mahmood
- Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - Gavin Cleary
- Alder Hey Children's NHS Foundation Trust, Liverpool, UK
| | - Elena Moraitis
- Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | | | - Phil Riley
- Royal Manchester Children's Hospital, Manchester, UK
| | | | - Seza Ozen
- Hacettepe University, Ankara, Turkey
| | | | | | - Pavla Dolezalova
- General University Hospital in Prague and Charles University, Prague, Czech Republic
| | | | | | | | - Nicola Ruperto
- Instituto Giannina Gaslini, IRCCS, UOSID Centro Trial, Genoa, Italy
| | | | - Despina Eleftheriou
- University College London Great Ormond Street Institute of Child Health and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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Prior Elicitation for Use in Clinical Trial Design and Analysis: A Literature Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18041833. [PMID: 33668623 PMCID: PMC7917693 DOI: 10.3390/ijerph18041833] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/01/2021] [Accepted: 02/09/2021] [Indexed: 11/16/2022]
Abstract
Bayesian inference is increasingly popular in clinical trial design and analysis. The subjective knowledge derived from an expert elicitation procedure may be useful to define a prior probability distribution when no or limited data is available. This work aims to investigate the state-of-the-art Bayesian prior elicitation methods with a focus on clinical trial research. A literature search on the Current Index to Statistics (CIS), PubMed, and Web of Science (WOS) databases, considering “prior elicitation” as a search string, was run on 1 November 2020. Summary statistics and trend of publications over time were reported. Finally, a Latent Dirichlet Allocation (LDA) model was developed to recognise latent topics in the pertinent papers retrieved. A total of 460 documents pertinent to the Bayesian prior elicitation were identified. Of these, 213 (45.4%) were published in the “Probability and Statistics” area. A total of 42 articles pertain to clinical trial and the majority of them (81%) reports parametric techniques as elicitation method. The last decade has seen an increased interest in prior elicitation and the gap between theory and application getting narrower and narrower. Given the promising flexibility of non-parametric approaches to the experts’ elicitation, more efforts are needed to ensure their diffusion also in applied settings.
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11
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Ozen S, Sag E. Childhood vasculitis. Rheumatology (Oxford) 2021; 59:iii95-iii100. [PMID: 32348513 DOI: 10.1093/rheumatology/kez599] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 11/04/2019] [Indexed: 12/19/2022] Open
Abstract
Vasculitis is a challenging disease for paediatricians. Certain vasculitides are quite common in children whereas others are much rarer compared with adults. The most common vasculitides in childhood are IgA-associated vasculitis (Henoch-Schönlein purpura) and Kawasaki disease, which are usually self-limiting vasculitides although children do develop complications as a result. We now have much better knowledge of how to manage these patients and prevent the deleterious complications. This review provides an up-to-date discussion on childhood vasculitides, including diagnosis, treatment and follow-up strategies, together with a comparison with vasculitides in adults. It also discusses the newly defined monogenic vasculitides that often present during early childhood.
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Affiliation(s)
- Seza Ozen
- Division of Pediatric Rheumatology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
| | - Erdal Sag
- Division of Pediatric Rheumatology, Department of Pediatrics, Hacettepe University, Ankara, Turkey
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12
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Veen D, Egberts MR, van Loey NEE, van de Schoot R. Expert Elicitation for Latent Growth Curve Models: The Case of Posttraumatic Stress Symptoms Development in Children With Burn Injuries. Front Psychol 2020; 11:1197. [PMID: 32625139 PMCID: PMC7314932 DOI: 10.3389/fpsyg.2020.01197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 05/07/2020] [Indexed: 12/24/2022] Open
Abstract
Experts provide an alternative source of information to classical data collection methods such as surveys. They can provide additional insight into problems, supplement existing data, or provide insights when classical data collection is troublesome. In this paper, we explore the (dis)similarities between expert judgments and data collected by traditional data collection methods regarding the development of posttraumatic stress symptoms (PTSSs) in children with burn injuries. By means of an elicitation procedure, the experts' domain expertise is formalized and represented in the form of probability distributions. The method is used to obtain beliefs from 14 experts, including nurses and psychologists. Those beliefs are contrasted with questionnaire data collected on the same issue. The individual and aggregated expert judgments are contrasted with the questionnaire data by means of Kullback-Leibler divergences. The aggregated judgments of the group that mainly includes psychologists resemble the questionnaire data more than almost all of the individual expert judgments.
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Affiliation(s)
- Duco Veen
- Department of Methodology and Statistics, Utrecht University, Utrecht, Netherlands
| | - Marthe R. Egberts
- Department of Clinical Psychology, Utrecht University, Utrecht, Netherlands
| | - Nancy E. E. van Loey
- Department of Clinical Psychology, Utrecht University, Utrecht, Netherlands
- Association of Dutch Burn Centres, Beverwijk, Netherlands
| | - Rens van de Schoot
- Department of Methodology and Statistics, Utrecht University, Utrecht, Netherlands
- Optentia Research Program, North-West University, Potchefstroom, South Africa
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13
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Alhussain ZA, Oakley JE. Assurance for clinical trial design with normally distributed outcomes: Eliciting uncertainty about variances. Pharm Stat 2020; 19:827-839. [PMID: 32537910 DOI: 10.1002/pst.2040] [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: 05/30/2019] [Revised: 02/14/2020] [Accepted: 05/12/2020] [Indexed: 02/03/2023]
Abstract
The assurance method is growing in popularity in clinical trial planning. The method involves eliciting a prior distribution for the treatment effect, and then calculating the probability that a proposed trial will produce a "successful" outcome. For normally distributed observations, uncertainty about the variance of the normal distribution also needs to be accounted for, but there is little guidance in the literature on how to elicit a distribution for a variance parameter. We present a simple elicitation method, and illustrate how the elicited distribution is incorporated within an assurance calculation. We also consider multi-stage trials, where a decision to proceed with a larger trial will follow from the outcome of a smaller trial; we illustrate the role of the elicited distribution in assessing the information provided by a proposed smaller trial. Free software is available for implementing our methods.
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Affiliation(s)
- Ziyad A Alhussain
- Mathematics Department, Faculty of Science in Zulfi, Majmaah University, Al Majma'ah, Saudi Arabia
| | - Jeremy E Oakley
- School of Mathematics and Statistics, The University of Sheffield, Sheffield, UK
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14
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de Graeff N, Groot N, Brogan P, Ozen S, Avcin T, Bader-Meunier B, Dolezalova P, Feldman BM, Kone-Paut I, Lahdenne P, Marks SD, McCann L, Pilkington C, Ravelli A, van Royen A, Uziel Y, Vastert B, Wulffraat N, Kamphuis S, Beresford MW. European consensus-based recommendations for the diagnosis and treatment of rare paediatric vasculitides - the SHARE initiative. Rheumatology (Oxford) 2020; 58:656-671. [PMID: 30535249 DOI: 10.1093/rheumatology/key322] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/04/2018] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The European initiative Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) aimed to optimize care for children with rheumatic diseases. Systemic vasculitides are very rare in children. Consequently, despite recent advances, paediatric-specific information is sparse. The lack of evidence-based recommendations is an important, unmet need. This study aimed to provide recommendations for diagnosing and treating children with rare forms of childhood systemic vasculitis. METHODS Recommendations were developed by a consensus process in accordance with the European League Against Rheumatism standard operating procedures. A systematic literature review informed the recommendations, which were devised and evaluated by a panel of experts via an online survey, and two consensus meetings using nominal group technique. Recommendations were accepted when ⩾ 80% of experts agreed. RESULTS Ninety-three relevant articles were found, and 78 recommendations were accepted in the two consensus meetings. General, cross-cutting recommendations and disease-specific statements regarding the diagnosis and treatment of childhood-onset PAN, granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, and Takayasu arteritis are provided. CONCLUSION These Single Hub and Access point for paediatric Rheumatology in Europe recommendations were formulated through an evidence-based consensus process to support uniform, high-quality standard of care for children with rare forms of paediatric systemic vasculitis.
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Affiliation(s)
- Nienke de Graeff
- Department of Paediatric Rheumatology, Wilhelmina Children's Hospital, Utrecht
| | - Noortje Groot
- Department of Paediatric Rheumatology, Wilhelmina Children's Hospital, Utrecht.,Department of Paediatric Rheumatology, Sophia Children's Hospital, Erasmus Medical Centre, Rotterdam, The Netherlands.,Department of Paediatric Rheumatology, Alder Hey Children's Hospital, Liverpool
| | - Paul Brogan
- Department of Paediatric Rheumatology, University College London Great Ormond Street Institute of Child Health and Great Ormond St Hospital for Children NHS Foundation Trust, London, UK
| | - Seza Ozen
- Department of Paediatric Rheumatology, Hacettepe University, Ankara, Turkey
| | - Tadej Avcin
- Department of Paediatric Rheumatology, University Children's Hospital Ljubljana, Ljubljana, Slovenia
| | - Brigitte Bader-Meunier
- Department of Paediatric Rheumatology, Necker Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Pavla Dolezalova
- 1st Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Brian M Feldman
- Department of Paediatric Rheumatology, The Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - Isabelle Kone-Paut
- Department of Paediatric Rheumatology, Bicêtre University Hospital, APHP, University of Paris Sud, Paris, France
| | - Pekka Lahdenne
- Department of Paediatric Rheumatology, Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland
| | - Stephen D Marks
- Department of Paediatric Rheumatology, University College London Great Ormond Street Institute of Child Health and Great Ormond St Hospital for Children NHS Foundation Trust, London, UK
| | - Liza McCann
- Department of Paediatric Rheumatology, Alder Hey Children's Hospital, Liverpool
| | - Clarissa Pilkington
- Department of Paediatric Rheumatology, University College London Great Ormond Street Institute of Child Health and Great Ormond St Hospital for Children NHS Foundation Trust, London, UK
| | - Angelo Ravelli
- Department of Paediatric Rheumatology, Gaslini Children's Hospital, Genoa, Italy
| | - Annet van Royen
- Department of Paediatric Rheumatology, Wilhelmina Children's Hospital, Utrecht
| | - Yosef Uziel
- Meir Medical Center, Kfar Saba, Tel Aviv University, Sackler School of Medicine, Tel Aviv, Israel
| | - Bas Vastert
- Department of Paediatric Rheumatology, Wilhelmina Children's Hospital, Utrecht
| | - Nico Wulffraat
- Department of Paediatric Rheumatology, Wilhelmina Children's Hospital, Utrecht
| | - Sylvia Kamphuis
- Department of Paediatric Rheumatology, Sophia Children's Hospital, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - Michael W Beresford
- Department of Paediatric Rheumatology, Alder Hey Children's Hospital, Liverpool.,Institute of Translational Medicine, University of Liverpool, Liverpool, UK
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15
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Cook JA, Julious SA, Sones W, Hampson LV, Hewitt C, Berlin JA, Ashby D, Emsley R, Fergusson DA, Walters SJ, Wilson EC, MacLennan G, Stallard N, Rothwell JC, Bland M, Brown L, Ramsay CR, Cook A, Armstrong D, Altman D, Vale LD. Practical help for specifying the target difference in sample size calculations for RCTs: the DELTA 2 five-stage study, including a workshop. Health Technol Assess 2019; 23:1-88. [PMID: 31661431 PMCID: PMC6843113 DOI: 10.3310/hta23600] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The randomised controlled trial is widely considered to be the gold standard study for comparing the effectiveness of health interventions. Central to its design is a calculation of the number of participants needed (the sample size) for the trial. The sample size is typically calculated by specifying the magnitude of the difference in the primary outcome between the intervention effects for the population of interest. This difference is called the 'target difference' and should be appropriate for the principal estimand of interest and determined by the primary aim of the study. The target difference between treatments should be considered realistic and/or important by one or more key stakeholder groups. OBJECTIVE The objective of the report is to provide practical help on the choice of target difference used in the sample size calculation for a randomised controlled trial for researchers and funder representatives. METHODS The Difference ELicitation in TriAls2 (DELTA2) recommendations and advice were developed through a five-stage process, which included two literature reviews of existing funder guidance and recent methodological literature; a Delphi process to engage with a wider group of stakeholders; a 2-day workshop; and finalising the core document. RESULTS Advice is provided for definitive trials (Phase III/IV studies). Methods for choosing the target difference are reviewed. To aid those new to the topic, and to encourage better practice, 10 recommendations are made regarding choosing the target difference and undertaking a sample size calculation. Recommended reporting items for trial proposal, protocols and results papers under the conventional approach are also provided. Case studies reflecting different trial designs and covering different conditions are provided. Alternative trial designs and methods for choosing the sample size are also briefly considered. CONCLUSIONS Choosing an appropriate sample size is crucial if a study is to inform clinical practice. The number of patients recruited into the trial needs to be sufficient to answer the objectives; however, the number should not be higher than necessary to avoid unnecessary burden on patients and wasting precious resources. The choice of the target difference is a key part of this process under the conventional approach to sample size calculations. This document provides advice and recommendations to improve practice and reporting regarding this aspect of trial design. Future work could extend the work to address other less common approaches to the sample size calculations, particularly in terms of appropriate reporting items. FUNDING Funded by the Medical Research Council (MRC) UK and the National Institute for Health Research as part of the MRC-National Institute for Health Research Methodology Research programme.
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Affiliation(s)
- Jonathan A Cook
- Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Steven A Julious
- Medical Statistics Group, School of Health and Related Research, University of Sheffield, Sheffield, UK
| | - William Sones
- Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Lisa V Hampson
- Statistical Methodology and Consulting, Novartis Pharma AG, Basel, Switzerland
| | - Catherine Hewitt
- York Trials Unit, Department of Health Sciences, University of York, York, UK
| | | | - Deborah Ashby
- Imperial Clinical Trials Unit, Imperial College London, London, UK
| | - Richard Emsley
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Dean A Fergusson
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Stephen J Walters
- Medical Statistics Group, School of Health and Related Research, University of Sheffield, Sheffield, UK
| | - Edward Cf Wilson
- Cambridge Centre for Health Services Research, Cambridge Clinical Trials Unit University of Cambridge, Cambridge, UK
- Health Economics Group, Norwich Medical School, University of East Anglia, Norwich, UK
| | - Graeme MacLennan
- Centre for Healthcare Randomised Trials, University of Aberdeen, Aberdeen, UK
| | - Nigel Stallard
- Warwick Medical School, Statistics and Epidemiology, University of Warwick, Coventry, UK
| | - Joanne C Rothwell
- Medical Statistics Group, School of Health and Related Research, University of Sheffield, Sheffield, UK
| | - Martin Bland
- Department of Health Sciences, University of York, York, UK
| | - Louise Brown
- MRC Clinical Trials Unit, Institute of Clinical Trials and Methodology, University College London, London, UK
| | - Craig R Ramsay
- Health Services Research Unit, University of Aberdeen, Aberdeen, UK
| | - Andrew Cook
- Wessex Institute, University of Southampton, Southampton, UK
| | - David Armstrong
- School of Population Health and Environmental Sciences, King's College London, London, UK
| | - Douglas Altman
- Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Luke D Vale
- Health Economics Group, Institute of Health & Society, Newcastle University, Newcastle upon Tyne, UK
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16
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Ramanan AV, Hampson LV, Lythgoe H, Jones AP, Hardwick B, Hind H, Jacobs B, Vasileiou D, Wadsworth I, Ambrose N, Davidson J, Ferguson PJ, Herlin T, Kavirayani A, Killeen OG, Compeyrot-Lacassagne S, Laxer RM, Roderick M, Swart JF, Hedrich CM, Beresford MW. Defining consensus opinion to develop randomised controlled trials in rare diseases using Bayesian design: An example of a proposed trial of adalimumab versus pamidronate for children with CNO/CRMO. PLoS One 2019; 14:e0215739. [PMID: 31166977 PMCID: PMC6550371 DOI: 10.1371/journal.pone.0215739] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 04/08/2019] [Indexed: 11/25/2022] Open
Abstract
Introduction Chronic nonbacterial osteomyelitis (CNO) is a rare autoinflammatory bone disorder primarily affecting children and adolescents. It can lead to chronic pain, bony deformities and fractures. The pathophysiology of CNO is incompletely understood. Scientific evidence suggests dysregulated expression of pro- and anti-inflammatory cytokines to be centrally involved. Currently, treatment is largely based on retrospective observational studies and expert opinion. Treatment usually includes nonsteroidal anti-inflammatory drugs and/or glucocorticoids, followed by a range of drugs in unresponsive cases. While randomised clinical trials are lacking, retrospective and prospective non-controlled studies suggest effectiveness of TNF inhibitors and bisphosphonates. The objective of the Bayesian consensus meeting was to quantify prior expert opinion. Methods Twelve international CNO experts were randomly chosen to be invited to a Bayesian prior elicitation meeting. Results Results showed that a typical new patient treated with pamidronate would have an 84% chance of improvement in their pain score relative to baseline at 26 weeks and an 83% chance on adalimumab. Experts thought there was a 50% chance that a new typical patient would record a pain score of 28mm (pamidronate) to 30mm (adalimumab) or better at 26 weeks. There was a modest trend in prior opinion to indicate an advantage of pamidronate vs adalimumab, with a 68% prior chance that pamidronate is superior to adalimumab by some margin. However, it is clear that there is considerable uncertainty about the precise relative merits of the two treatments. Conclusions The rarity of CNO leads to challenges in conducting randomised controlled trials with sufficient power to provide a definitive outcome. We address this using a Bayesian design, and here describe the process and outcome of the elicitation exercise to establish expert prior opinion. This opinion will be tested in the planned prospective CNO study. The process for establishing expert consensus opinion in CNO will be helpful for developing studies in other rare paediatric diseases.
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Affiliation(s)
- A. V. Ramanan
- Paediatric Rheumatology, Bristol Royal Hospital for Children, Bristol and Bristol Medical School, University of Bristol, Bristol, United Kingdom
- * E-mail:
| | - L. V. Hampson
- Statistical Methodology and Consulting, Novartis Pharma AG, Basel, Switzerland
| | - H Lythgoe
- Department of Women's & Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
- Department of Paediatric Rheumatology, Alder Hey Children’s NHS Foundation Trust, Liverpool, United Kingdom
| | - A. P. Jones
- Clinical Trials Research Centre, Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom
| | - B Hardwick
- Clinical Trials Research Centre, Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom
| | - H Hind
- Clinical Trials Research Centre, Department of Biostatistics, University of Liverpool, Liverpool, United Kingdom
| | - B Jacobs
- Paediatrics, Royal National Orthopaedic Hospital, London, United Kingdom
| | - D Vasileiou
- Department of Mathematics and Statistics, Fylde College, Lancaster University, Lancaster, United Kingdom
| | - I Wadsworth
- Department of Mathematics and Statistics, Fylde College, Lancaster University, Lancaster, United Kingdom
| | - N Ambrose
- Rheumatology, University College Hospital, London, United Kingdom
| | - J Davidson
- Paediatric Rheumatology, Royal Hospital for Children, Glasgow, United Kingdom
| | - P. J. Ferguson
- Stead Family Department of Pediatrics, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - T Herlin
- Department of Paediatrics, Aarhus University, Aarhus, Denmark
| | - A Kavirayani
- Paediatric Rheumatology, Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom
| | - O. G. Killeen
- National Centre for Paediatric Rheumatology, Our Lady’s Children Hospital, Crumlin, Dublin, Ireland
| | - S Compeyrot-Lacassagne
- Rheumatology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
| | - R. M. Laxer
- Department of Paediatrics, University of Toronto, The Hospital for Sick Children, Toronto, Canada
| | - M Roderick
- Paediatric Rheumatology, Bristol Royal Hospital for Children, Bristol and Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - J. F. Swart
- Paediatric Rheumatology, University Medical Centre Utrecht, Utrecht, Netherlands
| | - C. M. Hedrich
- Department of Women's & Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - M. W. Beresford
- Department of Women's & Children's Health, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
- Department of Paediatric Rheumatology, Alder Hey Children’s NHS Foundation Trust, Liverpool, United Kingdom
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17
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Berchialla P, Zohar S, Baldi I. Bayesian sample size determination for phase IIA clinical trials using historical data and semi-parametric prior's elicitation. Pharm Stat 2018; 18:198-211. [PMID: 30440109 DOI: 10.1002/pst.1914] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 09/13/2018] [Accepted: 10/17/2018] [Indexed: 11/10/2022]
Abstract
The Simon's two-stage design is the most commonly applied among multi-stage designs in phase IIA clinical trials. It combines the sample sizes at the two stages in order to minimize either the expected or the maximum sample size. When the uncertainty about pre-trial beliefs on the expected or desired response rate is high, a Bayesian alternative should be considered since it allows to deal with the entire distribution of the parameter of interest in a more natural way. In this setting, a crucial issue is how to construct a distribution from the available summaries to use as a clinical prior in a Bayesian design. In this work, we explore the Bayesian counterparts of the Simon's two-stage design based on the predictive version of the single threshold design. This design requires specifying two prior distributions: the analysis prior, which is used to compute the posterior probabilities, and the design prior, which is employed to obtain the prior predictive distribution. While the usual approach is to build beta priors for carrying out a conjugate analysis, we derived both the analysis and the design distributions through linear combinations of B-splines. The motivating example is the planning of the phase IIA two-stage trial on anti-HER2 DNA vaccine in breast cancer, where initial beliefs formed from elicited experts' opinions and historical data showed a high level of uncertainty. In a sample size determination problem, the impact of different priors is evaluated.
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Affiliation(s)
- Paola Berchialla
- Department of Clinical and Biological Sciences, University of Torino, Torino, Italy
| | - Sarah Zohar
- Centre de Recherche des Cordeliers, INSERM, Paris, France
| | - Ileana Baldi
- Department of Cardiac, Thoracic and Vascular Sciences, University of Padova, Padova, Italy
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18
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Faustino EVS, Shabanova V, Pinto MG, Li S, Trakas E, Miksa M, Gertz S, Polikoff LA, Napolitano M, Brudnicki AR, Tala JA, Silva CT. Epidemiology of Lower Extremity Deep Venous Thrombosis in Critically Ill Adolescents. J Pediatr 2018; 201:176-183.e2. [PMID: 29891258 DOI: 10.1016/j.jpeds.2018.05.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/03/2018] [Accepted: 05/03/2018] [Indexed: 12/22/2022]
Abstract
OBJECTIVE To determine the epidemiology of lower extremity deep venous thrombosis (DVT) in critically ill adolescents, which currently is unclear. STUDY DESIGN We performed a multicenter, prospective, cohort study. Adolescents aged 13-17 years who were admitted to 6 pediatric intensive care units and were anticipated to receive cardiopulmonary support for at least 48 hours were eligible, unless they were admitted with DVT or pulmonary embolism or were receiving or anticipated to receive therapeutic anticoagulation. While patients were in the unit, serial sonograms of the lower extremities were performed, then centrally adjudicated. Bayesian statistics were used to leverage the similarities between adults and adolescents. RESULTS A total of 88 adolescents were enrolled, from whom 184 lower extremity sonograms were performed. Of these, 9 adolescents developed DVT, with 1 having bilateral DVT. The frequency of DVT was 12.4% (95% credible interval: 6.1%, 20.1%), which ranged from 6.3% to 19.8% with a variability of 41.0% across units. All cases of DVT occurred in adolescents who received invasive mechanical ventilation (frequency: 16.5%; 95% credible interval 8.1%, 26.6%). DVT was associated with femoral central venous catheterization (OR 15.44; 95% credible interval 1.62, 69.05) and severe illness (OR for every 0.1 increase in risk of mortality 3.11; 95% credible interval 1.19, 6.85). DVT appears to be associated with prolonged days on support. CONCLUSIONS Our findings highlight the similarities and differences in the epidemiology of DVT between adults and adolescents. They support the conduct and inform the design of a trial of pharmacologic prophylaxis in critically ill adolescents.
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Affiliation(s)
| | | | - Matthew G Pinto
- Department of Pediatrics, New York Medical College, Valhalla, NY
| | - Simon Li
- Department of Pediatrics, New York Medical College, Valhalla, NY
| | - Erin Trakas
- Department of Pediatrics, University of Rochester Golisano Children's Hospital, Rochester, NY
| | - Michael Miksa
- Department of Pediatrics, Children's Hospital at Montefiore, Bronx, NY
| | - Shira Gertz
- Department of Pediatrics, Saint Barnabas Medical Center, Livingston, NJ
| | - Lee A Polikoff
- Department of Pediatrics, The Warren Alpert School of Medicine at Brown University, Providence, RI
| | - Massimo Napolitano
- Department of Diagnostic Radiology, Joseph M. Sanzari Children's Hospital at Hackensack University Medical Center, Hackensack, NJ
| | - Adele R Brudnicki
- Department of Diagnostic Radiology, New York Medical College, Valhalla, NY
| | - Joana A Tala
- Pediatric Intensive Care Unit, Yale-New Haven Children's Hospital, New Haven, CT
| | - Cicero T Silva
- Department of Diagnostic Radiology, Yale School of Medicine, New Haven, CT
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19
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Singh J, Santosh P. Key issues in Rett syndrome: emotional, behavioural and autonomic dysregulation (EBAD) - a target for clinical trials. Orphanet J Rare Dis 2018; 13:128. [PMID: 30064458 PMCID: PMC6069816 DOI: 10.1186/s13023-018-0873-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 07/10/2018] [Indexed: 02/02/2023] Open
Abstract
Complex neurodevelopmental disorders need multi-disciplinary treatment approaches for optimal care. The clinical effectiveness of treatments is limited in patients with rare genetic syndromes with multisystem morbidity. Emotional and behavioural dysregulation is common across many neurodevelopmental disorders. It can manifest in children across multiple diagnostic groups, including those on the autism spectrum and in rare genetic syndromes such as Rett Syndrome (RTT). There is, however a remarkable scarcity in the literature on the impact of the autonomic component on emotional and behavioural regulation in these disorders, and on the longer-term outcomes on disorder burden.RTT is a debilitating and often life-threatening disorder involving multiple overlapping physiological systems. Autonomic dysregulation otherwise known as dysautonomia is a cardinal feature of RTT characterised by an imbalance between the sympathetic and parasympathetic arms of the autonomic nervous system. Unlocking the autonomic component of emotional and behavioural dysregulation would be central in reducing the impairment seen in patients with RTT. In this vein, Emotional, Behavioural and Autonomic Dysregulation (EBAD) would be a useful construct to target for treatment which could mitigate burden and improve the quality of life of patients.RTT can be considered as a congenital dysautonomia and because EBAD can give rise to impairments occurring in multiple overlapping physiological systems, understanding these physiological responses arising out of EBAD would be a critical part to consider when planning treatment strategies and improving clinical outcomes in these patients. Biometric guided pharmacological and bio-feedback therapy for the behavioural and emotional aspects of the disorder offers an attracting perspective to manage EBAD in these patients. This can also allow for the stratification of patients into clinical trials and could ultimately help streamline the patient care pathway for optimal outcomes.The objectives of this review are to emphasise the key issues relating to the management of EBAD in patients with RTT, appraise clinical trials done in RTT from the perspective of autonomic physiology and to discuss the potential of EBAD as a target for clinical trials.
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Affiliation(s)
- Jatinder Singh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Paramala Santosh
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK. .,Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, UK.
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20
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Tingley K, Coyle D, Graham ID, Sikora L, Chakraborty P, Wilson K, Mitchell JJ, Stockler-Ipsiroglu S, Potter BK. Using a meta-narrative literature review and focus groups with key stakeholders to identify perceived challenges and solutions for generating robust evidence on the effectiveness of treatments for rare diseases. Orphanet J Rare Dis 2018; 13:104. [PMID: 29954425 PMCID: PMC6022712 DOI: 10.1186/s13023-018-0851-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 06/20/2018] [Indexed: 12/15/2022] Open
Abstract
INTRODUCTION For many rare diseases, strong analytic study designs for evaluating the efficacy and effectiveness of interventions are challenging to implement because of small, geographically dispersed patient populations and underlying clinical heterogeneity. The objective of this study was to integrate perspectives from published literature and key rare disease stakeholders to better understand the perceived challenges and proposed methodological approaches to research on clinical interventions for rare diseases. METHODS We used a meta-narrative literature review and focus group interviews with key rare disease stakeholders to better understand the perceived challenges in generating and synthesizing treatment effectiveness evidence, and to describe various research methods for mitigating these identified challenges. Data from both components of this study were synthesized narratively according to research paradigms that emerged from our data. RESULTS Results from our meta-narrative literature review and focus group interviews revealed three fundamental challenges in generating robust treatment effectiveness evidence for rare diseases: i) limitations in recruiting a sufficient sample size to achieve planned statistical power; ii) inability to account for clinical heterogeneity and assess treatment effects across a clinical spectrum; and iii) reliance on short-term, surrogate outcomes whose clinical relevance is often unclear. We mapped these challenges and associated solutions to three interrelated research paradigms: i) explanatory evidence generation; ii) comparative effectiveness/pragmatic evidence generation; and iii) patient-oriented evidence generation. Within each research paradigm, numerous criticisms and potential solutions have been described with respect to overcoming these challenges from a research study design perspective. CONCLUSIONS Over time, discussions about clinical research for interventions for rare diseases have moved beyond methodological approaches to overcome challenges related to explanatory evidence generation, with increased recognition of the importance of pragmatic and patient-oriented evidence. Future directions for our work include developing a framework to expand current evidence synthesis practices to take into consideration many of the concepts discussed in this paper.
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Affiliation(s)
- Kylie Tingley
- School of Epidemiology and Public Health, University of Ottawa, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
| | - Doug Coyle
- School of Epidemiology and Public Health, University of Ottawa, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
| | - Ian D. Graham
- School of Epidemiology and Public Health, University of Ottawa, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
- Ottawa Hospital Research Institute, Ottawa, ON Canada
| | - Lindsey Sikora
- Health Sciences Library, University of Ottawa, Ottawa, ON Canada
| | - Pranesh Chakraborty
- Metabolics and Newborn Screening, Department of Pediatrics, Children’s Hospital of Eastern Ontario, Ottawa, ON Canada
- Department of Pediatrics, University of Ottawa, Ottawa, ON Canada
- Newborn Screening Ontario, Ottawa, ON Canada
| | - Kumanan Wilson
- School of Epidemiology and Public Health, University of Ottawa, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
- Ottawa Hospital Research Institute, Ottawa, ON Canada
| | - John J. Mitchell
- Department of Pediatrics and Department of Medical Genetics, McGill University Health Centre, Montreal, QC, Canada
| | - Sylvia Stockler-Ipsiroglu
- Division of Biochemical Diseases, BC Children’s Hospital, Vancouver, BC Canada
- Department of Pediatrics, University of British Columbia, Vancouver, BC Canada
| | - Beth K. Potter
- School of Epidemiology and Public Health, University of Ottawa, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
| | - in collaboration with the Canadian Inherited Metabolic Diseases Research Network
- School of Epidemiology and Public Health, University of Ottawa, 600 Peter Morand Crescent, Ottawa, ON K1G 5Z3 Canada
- Ottawa Hospital Research Institute, Ottawa, ON Canada
- Health Sciences Library, University of Ottawa, Ottawa, ON Canada
- Metabolics and Newborn Screening, Department of Pediatrics, Children’s Hospital of Eastern Ontario, Ottawa, ON Canada
- Department of Pediatrics, University of Ottawa, Ottawa, ON Canada
- Newborn Screening Ontario, Ottawa, ON Canada
- Department of Pediatrics and Department of Medical Genetics, McGill University Health Centre, Montreal, QC, Canada
- Division of Biochemical Diseases, BC Children’s Hospital, Vancouver, BC Canada
- Department of Pediatrics, University of British Columbia, Vancouver, BC Canada
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21
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Dallow N, Best N, Montague TH. Better decision making in drug development through adoption of formal prior elicitation. Pharm Stat 2018; 17:301-316. [PMID: 29603614 DOI: 10.1002/pst.1854] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 01/26/2018] [Accepted: 02/08/2018] [Indexed: 11/10/2022]
Abstract
With the continued increase in the use of Bayesian methods in drug development, there is a need for statisticians to have tools to develop robust and defensible informative prior distributions. Whilst relevant empirical data should, where possible, provide the basis for such priors, it is often the case that limitations in data and/or our understanding may preclude direct construction of a data-based prior. Formal expert elicitation methods are a key technique that can be used to determine priors in these situations. Within GlaxoSmithKline, we have adopted a structured approach to prior elicitation on the basis of the SHELF elicitation framework and routinely use this in conjunction with calculation of probability of success (assurance) of the next study(s) to inform internal decision making at key project milestones. The aim of this paper is to share our experiences of embedding the use of prior elicitation within a large pharmaceutical company, highlighting both the benefits and challenges of prior elicitation through a series of case studies. We have found that putting team beliefs into the shape of a quantitative probability distribution provides a firm anchor for all internal decision making, enabling teams to provide investment boards with formally appropriate estimates of the probability of trial success as well as robust plans for interim decision rules where appropriate. As an added benefit, the elicitation process provides transparency about the beliefs and risks of the potential medicine, ultimately enabling better portfolio and company-wide decision making.
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Affiliation(s)
| | - Nicky Best
- GlaxoSmithKline, Uxbridge, Middlesex, UK
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22
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Sag E, Batu ED, Ozen S. Childhood systemic vasculitis. Best Pract Res Clin Rheumatol 2017; 31:558-575. [PMID: 29773273 DOI: 10.1016/j.berh.2017.11.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/16/2017] [Accepted: 11/20/2017] [Indexed: 01/19/2023]
Abstract
Vasculitides are characterized by inflammation of the vessel wall. Most of the vasculitides tend to occur in vessels of a specific size and certain target organs. In this review, we discuss each specific childhood vasculitis according to the latest Chapel Hill Consensus Conference 2012 nomenclature system and the Ankara 2008 classification criteria. We have also reviewed the clinical and laboratory characteristics and the recent treatment recommendations for the vasculitides we encounter in children.
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Affiliation(s)
- Erdal Sag
- Hacettepe University, Ihsan Dogramaci Children's Hospital, Department of Pediatric Rheumatology, Turkey
| | - Ezgi Deniz Batu
- Hacettepe University, Ihsan Dogramaci Children's Hospital, Department of Pediatric Rheumatology, Turkey
| | - Seza Ozen
- Hacettepe University, Ihsan Dogramaci Children's Hospital, Department of Pediatric Rheumatology, Turkey.
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23
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Vazquez-Romo KA, Rodriguez-Hernandez A, Paczka JA, Nuño-Suarez MA, Rocha-Muñoz AD, Zavala-Cerna MG. Optic Neuropathy Secondary to Polyarteritis Nodosa, Case Report, and Diagnostic Challenges. Front Neurol 2017; 8:490. [PMID: 28979236 PMCID: PMC5611380 DOI: 10.3389/fneur.2017.00490] [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: 06/29/2017] [Accepted: 09/01/2017] [Indexed: 11/22/2022] Open
Abstract
Purpose To describe a case of optic neuropathy as a primary manifestation of polyarteritis nodosa (PAN) and discuss diagnostic challenges. Methods Case report. Results A 41-year-old Hispanic man presented with a 2-day history of reduced visual acuity in his left eye. Physical examination revealed a complete visual field loss in the affected eye. Best-corrected visual acuity (BCVA) in the left eye was hand motion, and fundus examination revealed a hyperemic optic disk with blurred margins, swelling, retinal folds, dilated veins, and normal size arteries. BCVA in the right eye was 20/20; no anomalies were seen during examination of the fundus. The patient was started on oral corticosteroids and once the diagnosis of PAN was made, cyclophosphamide was added to the treatment regimen. Six months later, the patient recovered his BCVA to 20/20 in his left eye. Conclusion Rarely does optic neuropathy present as a primary manifestation of PAN; nevertheless, it represents an ophthalmologic emergency that requires expeditious anti-inflammatory and immunosuppressive treatment to decrease the probability of permanent visual damage. Unfortunately, diagnosing PAN is challenging as it necessitates a high index of suspicion. In young male patients who present for the first time with diminished visual acuity, ophthalmologists become cornerstones in the suspicion of this diagnosis and should be responsible for continuing the study until a diagnosis is reached to ensure rapid commencement of immunosuppressive treatment.
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Affiliation(s)
- Kristian A Vazquez-Romo
- Ophthalmology Department, Hospital Regional "Dr. Valentín Gómez Farías", Zapopan, Jalisco, México
| | - Adrian Rodriguez-Hernandez
- UIEC, Hospital de Especialidades, Centro Médico Nacional de Occidente (CMNO), Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco, México
| | - Jose A Paczka
- Unidad de Diagnóstico Temprano del Glaucoma, Guadalajara, Jalisco, México
| | - Moises A Nuño-Suarez
- Ophthalmology Department, Hospital Regional "Dr. Valentín Gómez Farías", Zapopan, Jalisco, México
| | - Alberto D Rocha-Muñoz
- Centro Universitario de Tonala (CUTONALA), Universidad de Guadalajara, Tonala, Jalisco, Mexico
| | - Maria G Zavala-Cerna
- Immunology Research Laboratory, Programa Internacional de Medicina, Universidad Autonoma de Guadalajara, Guadalajara, Jalisco, Mexico
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24
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Tian MQ, Liu SY, Li J, Shu XM. [Hypertension and intermittent convulsions for one month in a school-age child]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2017; 19:816-819. [PMID: 28697838 PMCID: PMC7389928 DOI: 10.7499/j.issn.1008-8830.2017.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 03/06/2017] [Indexed: 06/07/2023]
Abstract
Childhood polyarteritis nodosa (PAN) is a rare systemic vasculitis and the delayed diagnosis and treatment will cause high incidence of sequelae and high mortality. This article reports a girl with childhood PAN due to posterior reversible encephalopathy syndrome (PRES). The girl aged ten years was admitted to the hospital due to hypertension and convulsions for one month. She had complaints of headache, vomiting, and blurred vision before convulsions. At six months before admission, a mass was observed in the neck. The physical examination showed that she had hypertension and no abnormal findings in the central nervous system. The brain magnetic resonance imaging manifested long T1 and T2 signals, high signal intensities on fluid-attenuated inversion recovery (FLAIR) images, and iso-signal intensity on diffusion-weighted imaging in the white matter of the left occipital lobe. Therefore, the cause of convulsions was considered as PRES. Mass biopsy suggested PAN and no findings supported tuberculosis. The right kidney atrophy was observed by ultrasound examination. Emission computed tomography of the kidney showed multiple vascular stenosis and no blood perfusion in the right kidney, so PAN was confirmed. These findings suggest that PAN should be considered in patients with vasculitis who had involvements of multiple systems after excluding common vasculitis, such as Kawasaki disease and Henoch-Schönlein purpura. Biopsy and angiography should be performed as early as possible for timely diagnosis and treatment.
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Affiliation(s)
- Mao-Qiang Tian
- Department of Pediatrics, Affiliated Hospital of Zunyi Medical College, Zunyi, Guizhou 563003, China.
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25
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Santosh P, Lievesley K, Fiori F, Singh J. Development of the Tailored Rett Intervention and Assessment Longitudinal (TRIAL) database and the Rett Evaluation of Symptoms and Treatments (REST) Questionnaire. BMJ Open 2017; 7:e015342. [PMID: 28637735 PMCID: PMC5734452 DOI: 10.1136/bmjopen-2016-015342] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 04/12/2017] [Accepted: 04/21/2017] [Indexed: 01/02/2023] Open
Abstract
INTRODUCTION Rett syndrome (RTT) is a pervasive neurodevelopmental disorder that presents with deficits in brain functioning leading to language and learning regression, characteristic hand stereotypies and developmental delay. Different mutations in the gene implicated in RTT-methyl-CpG-binding protein 2 (MECP2) establishes RTT as a disorder with divergent symptomatology ranging from individuals with severe to milder phenotypes. A reliable and single multidimensional questionnaire is needed that can embrace all symptoms, and the relationships between them, and can map clinically meaningful data to symptomatology across the lifespan in patients with RTT. As part of the HealthTracker-based Tailored Rett Intervention and Assessment Longitudinal (TRIAL) database, the Rett Evaluation of Symptoms and Treatments (REST) Questionnaire will be able to marry with the physiological aspects of the disease obtained using wearable sensor technology, along with genetic and psychosocial data to stratify patients. Taken together, the web-based TRIAL database will empower clinicians and researchers with the confidence to delineate between different aspects of disorder symptomatology to streamline care pathways for individuals or for those patients entering clinical trials. This protocol describes the anticipated development of the REST questionnaire and the TRIAL database which links with the outcomes of the wearable sensor technology, and will serve as a barometer for longitudinal patient monitoring in patients with RTT. METHODS AND ANALYSIS The US Food and Drug Administration Guidance for Patient-Reported Outcome Measures will be used as a template to inform the methodology of the study. It will follow an iterative framework that will include item/concept identification, item/concept elicitation in parent/carer-mediated focus groups, expert clinician feedback, web-based presentation of questionnaires, initial scale development, instrument refinement and instrument validation. ETHICS AND DISSEMINATION The study has received favourable opinion from the National Health Service (NHS) Research Ethics Committee (REC): NHS Research Ethics Committee (REC)-London, Bromley Research Ethics Committee (reference: 15/LO/1772).
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Affiliation(s)
- Paramala Santosh
- Department of Child and Adolescent Psychiatry, King’s College London, London, UK
- HealthTracker Ltd, Gillingham, Kent, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, UK
| | - Kate Lievesley
- Department of Child and Adolescent Psychiatry, King’s College London, London, UK
- HealthTracker Ltd, Gillingham, Kent, UK
| | - Federico Fiori
- Department of Child and Adolescent Psychiatry, King’s College London, London, UK
- HealthTracker Ltd, Gillingham, Kent, UK
- Centre for Interventional Paediatric Psychopharmacology and Rare Diseases, South London and Maudsley NHS Foundation Trust, London, UK
| | - Jatinder Singh
- Department of Child and Adolescent Psychiatry, King’s College London, London, UK
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26
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Roderick MR, Sen ES, Ramanan AV. Chronic recurrent multifocal osteomyelitis in children and adults: current understanding and areas for development. Rheumatology (Oxford) 2017; 57:41-48. [DOI: 10.1093/rheumatology/kex066] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Indexed: 11/14/2022] Open
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27
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Eleftheriou D, Brogan PA. Therapeutic advances in the treatment of vasculitis. Pediatr Rheumatol Online J 2016; 14:26. [PMID: 27112923 PMCID: PMC4845429 DOI: 10.1186/s12969-016-0082-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 04/04/2016] [Indexed: 02/06/2023] Open
Abstract
Considerable therapeutic advances for the treatment of vasculitis of the young have been made in the past 10 years, including the development of outcome measures that facilitate clinical trial design. Notably, these include: a recognition that some patients with Kawasaki Disease require corticosteroids as primary treatment combined with IVIG; implementation of rare disease trial design for polyarteritis nodosa to deliver the first randomised controlled trial for children; first clinical trials involving children for anti-neutrophil cytoplasmic antibody (ANCA) vasculitis; and identification of monogenic forms of vasculitis that provide an understanding of pathogenesis, thus facilitating more targeted treatment. Robust randomised controlled trials for Henoch Schönlein Purpura nephritis and Takayasu arteritis are needed; there is also an over-arching need for trials examining new agents that facilitate corticosteroid sparing, of particular importance in the paediatric population since glucocorticoid toxicity is a major concern.
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Affiliation(s)
- Despina Eleftheriou
- ARUK centre for Paediatric and Adolescent Rheumatology, Institute of Child Health and Great Ormond St Hospital NHS Foundation Trust, 30 Guilford Street, London, WC1N 1EH, UK.
| | - Paul A Brogan
- Department of Paediatric Rheumatology, Institute of Child Health and Great Ormond St Hospital NHS Foundation Trust, 30 Guilford Street, London, WC1 E1N, UK
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28
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Katz DM, Bird A, Coenraads M, Gray SJ, Menon DU, Philpot BD, Tarquinio DC. Rett Syndrome: Crossing the Threshold to Clinical Translation. Trends Neurosci 2016; 39:100-113. [PMID: 26830113 PMCID: PMC4924590 DOI: 10.1016/j.tins.2015.12.008] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 12/14/2015] [Accepted: 12/15/2015] [Indexed: 12/11/2022]
Abstract
Lying at the intersection between neurobiology and epigenetics, Rett syndrome (RTT) has garnered intense interest in recent years, not only from a broad range of academic scientists, but also from the pharmaceutical and biotechnology industries. In addition to the critical need for treatments for this devastating disorder, optimism for developing RTT treatments derives from a unique convergence of factors, including a known monogenic cause, reversibility of symptoms in preclinical models, a strong clinical research infrastructure highlighted by an NIH-funded natural history study and well-established clinics with significant patient populations. Here, we review recent advances in understanding the biology of RTT, particularly promising preclinical findings, lessons from past clinical trials, and critical elements of trial design for rare disorders.
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Affiliation(s)
- David M Katz
- Departments of Neurosciences and Psychiatry, Case Western Reserve University School of Medicine, 10900 Euclid Avenue, Cleveland, OH 44106, USA.
| | - Adrian Bird
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Monica Coenraads
- Rett Syndrome Research Trust, 67 Under Cliff Road, Trumbull, CT 06611, USA
| | - Steven J Gray
- Gene Therapy Center and Department of Ophthalmology, University of North Carolina, Chapel Hill, NC USA
| | - Debashish U Menon
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Benjamin D Philpot
- Department of Cell Biology and Physiology, Neuroscience Center, and Carolina Institute for Developmental Disabilities, UNC School of Medicine, Chapel Hill, NC 27599, USA
| | - Daniel C Tarquinio
- Children's Healthcare of Atlanta, Emory University, 1605 Chantilly Drive NE, Atlanta, GA 30324, USA
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29
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Hampson LV, Whitehead J, Eleftheriou D, Brogan P. Bayesian methods for the design and interpretation of clinical trials in very rare diseases. Stat Med 2014; 33:4186-201. [PMID: 24957522 PMCID: PMC4260127 DOI: 10.1002/sim.6225] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 04/07/2014] [Accepted: 05/17/2014] [Indexed: 11/29/2022]
Abstract
This paper considers the design and interpretation of clinical trials comparing treatments for conditions so rare that worldwide recruitment efforts are likely to yield total sample sizes of 50 or fewer, even when patients are recruited over several years. For such studies, the sample size needed to meet a conventional frequentist power requirement is clearly infeasible. Rather, the expectation of any such trial has to be limited to the generation of an improved understanding of treatment options. We propose a Bayesian approach for the conduct of rare-disease trials comparing an experimental treatment with a control where patient responses are classified as a success or failure. A systematic elicitation from clinicians of their beliefs concerning treatment efficacy is used to establish Bayesian priors for unknown model parameters. The process of determining the prior is described, including the possibility of formally considering results from related trials. As sample sizes are small, it is possible to compute all possible posterior distributions of the two success rates. A number of allocation ratios between the two treatment groups can be considered with a view to maximising the prior probability that the trial concludes recommending the new treatment when in fact it is non-inferior to control. Consideration of the extent to which opinion can be changed, even by data from the best feasible design, can help to determine whether such a trial is worthwhile.
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Affiliation(s)
- Lisa V Hampson
- Medical and Pharmaceutical Statistics Research Unit, Department of Mathematics and Statistics, Lancaster UniversityLancaster, LA1 4YF, U.K.
| | - John Whitehead
- Medical and Pharmaceutical Statistics Research Unit, Department of Mathematics and Statistics, Lancaster UniversityLancaster, LA1 4YF, U.K.
| | - Despina Eleftheriou
- Department of Paediatric Rheumatology, UCL Institute of Child Health30 Guilford Street, London WC1N 1EH, U.K.
| | - Paul Brogan
- Department of Paediatric Rheumatology, UCL Institute of Child Health30 Guilford Street, London WC1N 1EH, U.K.
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