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White IR, Szubert AJ, Choodari-Oskooei B, Walker AS, Parmar MKB. When should factorial designs be used for late-phase randomised controlled trials? Clin Trials 2024; 21:162-170. [PMID: 37904490 PMCID: PMC7615816 DOI: 10.1177/17407745231206261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
BACKGROUND A 2×2 factorial design evaluates two interventions (A versus control and B versus control) by randomising to control, A-only, B-only or both A and B together. Extended factorial designs are also possible (e.g. 3×3 or 2×2×2). Factorial designs often require fewer resources and participants than alternative randomised controlled trials, but they are not widely used. We identified several issues that investigators considering this design need to address, before they use it in a late-phase setting. METHODS We surveyed journal articles published in 2000-2022 relating to designing factorial randomised controlled trials. We identified issues to consider based on these and our personal experiences. RESULTS We identified clinical, practical, statistical and external issues that make factorial randomised controlled trials more desirable. Clinical issues are (1) interventions can be easily co-administered; (2) risk of safety issues from co-administration above individual risks of the separate interventions is low; (3) safety or efficacy data are wanted on the combination intervention; (4) potential for interaction (e.g. effect of A differing when B administered) is low; (5) it is important to compare interventions with other interventions balanced, rather than allowing randomised interventions to affect the choice of other interventions; (6) eligibility criteria for different interventions are similar. Practical issues are (7) recruitment is not harmed by testing many interventions; (8) each intervention and associated toxicities is unlikely to reduce either adherence to the other intervention or overall follow-up; (9) blinding is easy to implement or not required. Statistical issues are (10) a suitable scale of analysis can be identified; (11) adjustment for multiplicity is not required; (12) early stopping for efficacy or lack of benefit can be done effectively. External issues are (13) adequate funding is available and (14) the trial is not intended for licensing purposes. An overarching issue (15) is that factorial design should give a lower sample size requirement than alternative designs. Across designs with varying non-adherence, retention, intervention effects and interaction effects, 2×2 factorial designs require lower sample size than a three-arm alternative when one intervention effect is reduced by no more than 24%-48% in the presence of the other intervention compared with in the absence of the other intervention. CONCLUSIONS Factorial designs are not widely used and should be considered more often using our issues to consider. Low potential for at most small to modest interaction is key, for example, where the interventions have different mechanisms of action or target different aspects of the disease being studied.
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Affiliation(s)
- Ian R White
- Ian R White, MRC Clinical Trials Unit at UCL, 2nd Floor, 90 High Holborn, London WC1V 6LJ, UK.
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2
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Haviari S, Mentré F. Distributive randomization: a pragmatic fractional factorial design to screen or evaluate multiple simultaneous interventions in a clinical trial. BMC Med Res Methodol 2024; 24:64. [PMID: 38468221 DOI: 10.1186/s12874-024-02191-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 02/23/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND In some medical indications, numerous interventions have a weak presumption of efficacy, but a good track record or presumption of safety. This makes it feasible to evaluate them simultaneously. This study evaluates a pragmatic fractional factorial trial design that randomly allocates a pre-specified number of interventions to each participant, and statistically tests main intervention effects. We compare it to factorial trials, parallel-arm trials and multiple head-to-head trials, and derive some good practices for its design and analysis. METHODS We simulated various scenarios involving 4 to 20 candidate interventions among which 2 to 8 could be simultaneously allocated. A binary outcome was assumed. One or two interventions were assumed effective, with various interactions (positive, negative, none). Efficient combinatorics algorithms were created. Sample sizes and power were obtained by simulations in which the statistical test was either difference of proportions or multivariate logistic regression Wald test with or without interaction terms for adjustment, with Bonferroni multiplicity-adjusted alpha risk for both. Native R code is provided without need for compiling or packages. RESULTS Distributive trials reduce sample sizes 2- to sevenfold compared to parallel arm trials, and increase them 1- to twofold compared to factorial trials, mostly when fewer allocations than for the factorial design are possible. An unexpectedly effective intervention causes small decreases in power (< 10%) if its effect is additive, but large decreases (possibly down to 0) if not, as for factorial designs. These large decreases are prevented by using interaction terms to adjust the analysis, but these additional estimands have a sample size cost and are better pre-specified. The issue can also be managed by adding a true control arm without any intervention. CONCLUSION Distributive randomization is a viable design for mass parallel evaluation of interventions in constrained trial populations. It should be introduced first in clinical settings where many undercharacterized interventions are potentially available, such as disease prevention strategies, digital behavioral interventions, dietary supplements for chronic conditions, or emerging diseases. Pre-trial simulations are recommended, for which tools are provided.
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Affiliation(s)
- Skerdi Haviari
- Université Paris Cité, Inserm, IAME, Paris, 75018, France.
- Département Epidémiologie Biostatistiques Et Recherche Clinique, AP-HP, Hôpital Bichat, Paris, 75018, France.
| | - France Mentré
- Université Paris Cité, Inserm, IAME, Paris, 75018, France
- Département Epidémiologie Biostatistiques Et Recherche Clinique, AP-HP, Hôpital Bichat, Paris, 75018, France
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Kahan BC, Hall SS, Beller EM, Birchenall M, Chan AW, Elbourne D, Little P, Fletcher J, Golub RM, Goulao B, Hopewell S, Islam N, Zwarenstein M, Juszczak E, Montgomery AA. Reporting of Factorial Randomized Trials: Extension of the CONSORT 2010 Statement. JAMA 2023; 330:2106-2114. [PMID: 38051324 DOI: 10.1001/jama.2023.19793] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Importance Transparent reporting of randomized trials is essential to facilitate critical appraisal and interpretation of results. Factorial trials, in which 2 or more interventions are assessed in the same set of participants, have unique methodological considerations. However, reporting of factorial trials is suboptimal. Objective To develop a consensus-based extension to the Consolidated Standards of Reporting Trials (CONSORT) 2010 Statement for factorial trials. Design Using the Enhancing the Quality and Transparency of Health Research (EQUATOR) methodological framework, the CONSORT extension for factorial trials was developed by (1) generating a list of reporting recommendations for factorial trials using a scoping review of methodological articles identified using a MEDLINE search (from inception to May 2019) and supplemented with relevant articles from the personal collections of the authors; (2) a 3-round Delphi survey between January and June 2022 to identify additional items and assess the importance of each item, completed by 104 panelists from 14 countries; and (3) a hybrid consensus meeting attended by 15 panelists to finalize the selection and wording of items for the checklist. Findings This CONSORT extension for factorial trials modifies 16 of the 37 items in the CONSORT 2010 checklist and adds 1 new item. The rationale for the importance of each item is provided. Key recommendations are (1) the reason for using a factorial design should be reported, including whether an interaction is hypothesized, (2) the treatment groups that form the main comparisons should be clearly identified, and (3) for each main comparison, the estimated interaction effect and its precision should be reported. Conclusions and Relevance This extension of the CONSORT 2010 Statement provides guidance on the reporting of factorial randomized trials and should facilitate greater understanding of and transparency in their reporting.
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Affiliation(s)
| | - Sophie S Hall
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Elaine M Beller
- Institute for Evidence-Based Healthcare, Bond University, Queensland, Australia
| | - Megan Birchenall
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - An-Wen Chan
- Women's College Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Diana Elbourne
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Paul Little
- Primary Care Research Centre, School of Primary Care, Population Sciences and Medical Education, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - John Fletcher
- The BMJ, BMA House, Tavistock Square, London, United Kingdom
| | - Robert M Golub
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Beatriz Goulao
- Health Services Research Unit, University of Aberdeen, Aberdeen, Scotland
| | - Sally Hopewell
- Oxford Clinical Trials Research Unit, University of Oxford, Oxford, United Kingdom
| | - Nazrul Islam
- Primary Care Research Centre, School of Primary Care, Population Sciences and Medical Education, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- The BMJ, BMA House, Tavistock Square, London, United Kingdom
| | - Merrick Zwarenstein
- Centre For Studies in Family Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Edmund Juszczak
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Alan A Montgomery
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
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4
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Kahan BC, Hall SS, Beller EM, Birchenall M, Elbourne D, Juszczak E, Little P, Fletcher J, Golub RM, Goulao B, Hopewell S, Islam N, Zwarenstein M, Chan AW, Montgomery AA. Consensus Statement for Protocols of Factorial Randomized Trials: Extension of the SPIRIT 2013 Statement. JAMA Netw Open 2023; 6:e2346121. [PMID: 38051535 DOI: 10.1001/jamanetworkopen.2023.46121] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2023] Open
Abstract
Importance Trial protocols outline a trial's objectives as well as the methods (design, conduct, and analysis) that will be used to meet those objectives, and transparent reporting of trial protocols ensures objectives are clear and facilitates appraisal regarding the suitability of study methods. Factorial trials, in which 2 or more interventions are assessed in the same set of participants, have unique methodological considerations. However, no extension of the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 Statement, which provides guidance on reporting of trial protocols, for factorial trials is available. Objective To develop a consensus-based extension to the SPIRIT 2013 Statement for factorial trials. Evidence Review The SPIRIT extension for factorial trials was developed using the Enhancing the Quality and Transparency of Health Research (EQUATOR) methodological framework. First, a list of reporting recommendations was generated using a scoping review of methodological articles identified using a MEDLINE search (inception to May 2019), which was supplemented with relevant articles from the personal collections of the authors. Second, a 3-round Delphi survey (January to June 2022, completed by 104 panelists from 14 countries) was conducted to assess the importance of items and identify additional recommendations. Third, a hybrid consensus meeting was held, attended by 15 panelists to finalize selection and wording of the checklist. Findings This SPIRIT extension for factorial trials modified 9 of the 33 items in the SPIRIT 2013 checklist. Key reporting recommendations were that the rationale for using a factorial design should be provided, including whether an interaction is hypothesized; the treatment groups that will form the main comparisons should be identified; and statistical methods for each main comparison should be provided, including how interactions will be assessed. Conclusions and Relevance In this consensus statement, 9 factorial-specific items were provided that should be addressed in all protocols of factorial trials to increase the trial's utility and transparency.
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Affiliation(s)
| | - Sophie S Hall
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Elaine M Beller
- Institute for Evidence-Based Healthcare, Bond University, Robina, Australia
| | - Megan Birchenall
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Diana Elbourne
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Edmund Juszczak
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
| | - Paul Little
- Primary Care Research Centre, School of Primary Care, Population Sciences and Medical Education, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | | | - Robert M Golub
- Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Beatriz Goulao
- Health Services Research Unit, University of Aberdeen, Aberdeen, Scotland
| | - Sally Hopewell
- Oxford Clinical Trials Research Unit, University of Oxford, Oxford, United Kingdom
| | - Nazrul Islam
- Primary Care Research Centre, School of Primary Care, Population Sciences and Medical Education, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- The BMJ, London, United Kingdom
| | - Merrick Zwarenstein
- Centre For Studies in Family Medicine, Schulich School of Medicine and Dentistry, Western University, London, Canada
| | - An-Wen Chan
- Women's College Research Institute, University of Toronto, Toronto, Canada
| | - Alan A Montgomery
- Nottingham Clinical Trials Unit, School of Medicine, University of Nottingham, Nottingham, United Kingdom
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5
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Mastrantoni L, Daniele G, Bria E. Extension of the SPIRIT 2013 Statement for Factorial Randomized Trials-A Step Toward Transparency and the Curse of Interaction. JAMA Netw Open 2023; 6:e2346124. [PMID: 38051534 DOI: 10.1001/jamanetworkopen.2023.46124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2023] Open
Affiliation(s)
- Luca Mastrantoni
- Medical Oncology, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Gennaro Daniele
- Unità Operative Complesse Phase I, Fondazione Policlinico Universitario Agostino Gemelli Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy
| | - Emilio Bria
- Medical Oncology, Università Cattolica del Sacro Cuore, Rome, Italy
- Comprehensive Cancer Center, Fondazione Policlinico Universitario Agostino Gemelli, Istituto di Ricovero e Cura a Carattere Scientifico, Rome, Italy
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Sremakaew M, Jull G, Treleaven J, Uthaikhup S. Effectiveness of adding rehabilitation of cervical related sensorimotor control to manual therapy and exercise for neck pain: A randomized controlled trial. Musculoskelet Sci Pract 2023; 63:102690. [PMID: 36414518 DOI: 10.1016/j.msksp.2022.102690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/29/2022] [Accepted: 09/04/2022] [Indexed: 11/13/2022]
Abstract
BACKGROUND Local neck treatments and sensorimotor training can improve cervical proprioception and balance, but it remains unclear what treatments and treatment combination achieve the best outcomes. OBJECTIVES To investigate the most effective interventions to improve disturbances in joint position sense (JPS) and balance and their effects on neck pain, dizziness and related features in the short- and long-terms. DESIGN 2x2 factorial, randomized controlled trial. METHODS Participants with neck pain (n = 152) were randomly allocated to one of four intervention groups: i) local neck treatment (NT), ii) NT + JPS/oculomotor exercises (JPS/OC), iii) NT + balance exercises, and iv) all treatments. Participants received 12 treatments over 6 weeks. Primary outcomes were postural sway and joint position error. Secondary outcomes included gait speed, dizziness, pain intensity and disability, cervical range of motion, functional ability, and quality of life. Outcome measures were taken at baseline, posttreatment and 3-, 6- and 12-month follow-ups. RESULTS All four interventions resulted in short- and long-term improvements in primary and secondary outcomes with medium to large effect sizes, but JPS and balance in neck torsion improved most with the addition of a combined program of JPS/OC + balance exercises to NT while balance in neck neutral improved most with the addition of balance exercises. Adding sensorimotor training was also more effective in maintaining levels of improvement in neck pain and disability at 6- and 12-months. Effect sizes of additional treatment benefits were medium to large. CONCLUSIONS Adding specific training of JPS/OC and balance to NT best addresses deficits in cervical proprioception and balance. CLINICAL TRIAL REGISTRATION NUMBER xxxxx.
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Affiliation(s)
- Munlika Sremakaew
- Department of Physical Therapy, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
| | - Gwendolen Jull
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Brisbane, Australia
| | - Julia Treleaven
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, Brisbane, Australia
| | - Sureeporn Uthaikhup
- Department of Physical Therapy, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.
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7
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Kwasnicka D, Keller J, Perski O, Potthoff S, Ten Hoor GA, Ainsworth B, Crutzen R, Dohle S, van Dongen A, Heino M, Henrich JF, Knox L, König LM, Maltinsky W, McCallum C, Nalukwago J, Neter E, Nurmi J, Spitschan M, Van Beurden SB, Van der Laan LN, Wunsch K, Levink JJJ, Sanderman R. White Paper: Open Digital Health - accelerating transparent and scalable health promotion and treatment. Health Psychol Rev 2022; 16:475-491. [PMID: 35240931 DOI: 10.1080/17437199.2022.2046482] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In this White Paper, we outline recommendations from the perspective of health psychology and behavioural science, addressing three research gaps: (1) What methods in the health psychology research toolkit can be best used for developing and evaluating digital health tools? (2) What are the most feasible strategies to reuse digital health tools across populations and settings? (3) What are the main advantages and challenges of sharing (openly publishing) data, code, intervention content and design features of digital health tools? We provide actionable suggestions for researchers joining the continuously growing Open Digital Health movement, poised to revolutionise health psychology research and practice in the coming years. This White Paper is positioned in the current context of the COVID-19 pandemic, exploring how digital health tools have rapidly gained popularity in 2020-2022, when world-wide health promotion and treatment efforts rapidly shifted from face-to-face to remote delivery. This statement is written by the Directors of the not-for-profit Open Digital Health initiative (n = 6), Experts attending the European Health Psychology Society Synergy Expert Meeting (n = 17), and the initiative consultant, following a two-day meeting (19-20th August 2021).
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Affiliation(s)
- Dominika Kwasnicka
- NHMRC CRE in Digital Technology to Transform Chronic Disease Outcomes, Melbourne School of Population and Global Health, University of Melbourne, Melbourne, Australia.,Faculty of Psychology, SWPS University of Social Sciences and Humanities, Wrocław, Poland
| | - Jan Keller
- Department of Education and Psychology; Freie Universität Berlin, Berlin, Germany
| | - Olga Perski
- Department of Behavioural Science and Health, University College London, London, UK
| | - Sebastian Potthoff
- Department of Social Work, Education and Community Wellbeing, Northumbria University, Newcastle upon Tyne, UK
| | - Gill A Ten Hoor
- Department of Work & Social Psychology, Maastricht University, Maastricht, The Netherlands
| | - Ben Ainsworth
- Department of Psychology, University of Bath, Bath, UK
| | - Rik Crutzen
- Department of Health Promotion, Maastricht University/CAPHRI, Maastricht, the Netherlands
| | - Simone Dohle
- Department of Psychology, University of Cologne, Cologne, Germany and Institute of General Practice and Family Medicine, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Anne van Dongen
- Department of Psychology, Health, and Technology, University of Twente, Enschede, the Netherlands
| | - Matti Heino
- Faculty of Social Sciences, University of Helsinki, Helsinki, Finland
| | - Julia F Henrich
- Faculty of Social and Behavioural Sciences, Leiden University, Institute of Psychology, Unit of Health-, Medical- and Neuropsychology, Leiden, The Netherlands
| | - Liam Knox
- Sheffield Institute for Translational Neuroscience, The University of Sheffield, Sheffield, UK
| | - Laura M König
- Faculty of Life Sciences, University of Bayreuth, Bayreuth, Germany
| | - Wendy Maltinsky
- Faculty of Natural Sciences, Division of Psychology, University of Stirling, Stirling, UK
| | - Claire McCallum
- Centre for Digital Health and Care, Faculty of Engineering, University of Bristol, Bristol, UK
| | - Judith Nalukwago
- Center for Communication Programs, USAID-Social and Behavior Change Activity, Johns Hopkins University Bloomberg School of Public Health, Kampala, Uganda
| | - Efrat Neter
- Department of Behavioral Sciences, Ruppin Academic Center, Emeq Hefer, Israel
| | - Johanna Nurmi
- Faculty of Social Sciences, University of Helsinki, Helsinki, Finland.,University of Cambridge, Behavioural Science Group, Primary Care Unit, Institute of Public Health, Forvie Site, Cambridge, UK
| | - Manuel Spitschan
- TUM Department of Sport and Health Sciences (TUM SG), Technical University of Munich, Munich, Germany and Translational Sensory and Circadian Neuroscience, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | | | - L Nynke Van der Laan
- Department of Communication and Cognition, Tilburg University, Tilburg, The Netherlands
| | - Kathrin Wunsch
- Karlsruhe Institute of Technology, Institute of Sports and Sports Science, Karlsruhe, Germany
| | - Jasper J J Levink
- Levink Life Sciences BV & Stichting Feniks Ontwikkelingsbegeleiding, Utrecht, The Netherlands
| | - Robbert Sanderman
- Department of Psychology, Health, and Technology, University of Twente, Enschede, the Netherlands.,Department of Health Psychology, University Medical Center Groningen University of Groningen, Groningen, The Netherlands
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8
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Kahan BC, Morris TP, Goulão B, Carpenter J. Estimands for factorial trials. Stat Med 2022; 41:4299-4310. [PMID: 35751568 PMCID: PMC9542167 DOI: 10.1002/sim.9510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 06/04/2022] [Accepted: 06/16/2022] [Indexed: 11/25/2022]
Abstract
Factorial trials offer an efficient method to evaluate multiple interventions in a single trial, however the use of additional treatments can obscure research objectives, leading to inappropriate analytical methods and interpretation of results. We define a set of estimands for factorial trials, and describe a framework for applying these estimands, with the aim of clarifying trial objectives and ensuring appropriate primary and sensitivity analyses are chosen. This framework is intended for use in factorial trials where the intent is to conduct "two-trials-in-one" (ie, to separately evaluate the effects of treatments A and B), and is comprised of four steps: (i) specifying how additional treatment(s) (eg, treatment B) will be handled in the estimand, and how intercurrent events affecting the additional treatment(s) will be handled; (ii) designating the appropriate factorial estimator as the primary analysis strategy; (iii) evaluating the interaction to assess the plausibility of the assumptions underpinning the factorial estimator; and (iv) performing a sensitivity analysis using an appropriate multiarm estimator to evaluate to what extent departures from the underlying assumption of no interaction may affect results. We show that adjustment for other factors is necessary for noncollapsible effect measures (such as odds ratio), and through a trial re-analysis we find that failure to consider the estimand could lead to inappropriate interpretation of results. We conclude that careful use of the estimands framework clarifies research objectives and reduces the risk of misinterpretation of trial results, and should become a standard part of both the protocol and reporting of factorial trials.
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Affiliation(s)
| | | | - Beatriz Goulão
- Health Services Research Unit, University of Aberdeen, Aberdeen, UK
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9
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Alfonso F, de la Torre Hernández JM, Ibáñez B, Sabaté M, Pan M, Gulati R, Saw J, Angiolillo DJ, Adlam D, Sánchez-madrid F. Diseño y justificación del estudio clínico aleatorizado BA-SCAD (bloqueadores beta y agentes antiplaquetarios en pacientes con disección arterial coronaria espontánea). Rev Esp Cardiol 2022; 75:515-22. [DOI: 10.1016/j.recesp.2021.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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10
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Tian Z, Esserman D, Tong G, Blaha O, Dziura J, Peduzzi P, Li F. Sample size calculation in hierarchical 2×2 factorial trials with unequal cluster sizes. Stat Med 2022; 41:645-664. [PMID: 34978097 PMCID: PMC8962918 DOI: 10.1002/sim.9284] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 11/19/2021] [Accepted: 11/25/2021] [Indexed: 11/08/2022]
Abstract
Motivated by a suicide prevention trial with hierarchical treatment allocation (cluster-level and individual-level treatments), we address the sample size requirements for testing the treatment effects as well as their interaction. We assume a linear mixed model, within which two types of treatment effect estimands (controlled effect and marginal effect) are defined. For each null hypothesis corresponding to an estimand, we derive sample size formulas based on large-sample z-approximation, and provide finite-sample modifications based on a t-approximation. We relax the equal cluster size assumption and express the sample size formulas as functions of the mean and coefficient of variation of cluster sizes. We show that the sample size requirement for testing the controlled effect of the cluster-level treatment is more sensitive to cluster size variability than that for testing the controlled effect of the individual-level treatment; the same observation holds for testing the marginal effects. In addition, we show that the sample size for testing the interaction effect is proportional to that for testing the controlled or the marginal effect of the individual-level treatment. We conduct extensive simulations to validate the proposed sample size formulas, and find the empirical power agrees well with the predicted power for each test. Furthermore, the t-approximations often provide better control of type I error rate with a small number of clusters. Finally, we illustrate our sample size formulas to design the motivating suicide prevention factorial trial. The proposed methods are implemented in the R package H2x2Factorial.
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Affiliation(s)
- Zizhong Tian
- Department of Biostatistics, Yale University School of Public Health, Connecticut, USA
| | - Denise Esserman
- Department of Biostatistics, Yale University School of Public Health, Connecticut, USA,Yale Center for Analytical Sciences, Yale University, Connecticut, USA
| | - Guangyu Tong
- Department of Biostatistics, Yale University School of Public Health, Connecticut, USA,Yale Center for Analytical Sciences, Yale University, Connecticut, USA
| | - Ondrej Blaha
- Department of Biostatistics, Yale University School of Public Health, Connecticut, USA,Yale Center for Analytical Sciences, Yale University, Connecticut, USA
| | - James Dziura
- Department of Biostatistics, Yale University School of Public Health, Connecticut, USA,Yale Center for Analytical Sciences, Yale University, Connecticut, USA
| | - Peter Peduzzi
- Department of Biostatistics, Yale University School of Public Health, Connecticut, USA,Yale Center for Analytical Sciences, Yale University, Connecticut, USA
| | - Fan Li
- Department of Biostatistics, Yale University School of Public Health, Connecticut, USA,Yale Center for Analytical Sciences, Yale University, Connecticut, USA,Center for Methods in Implementation and Prevention Science, Yale University, Connecticut, USA,Correspondence Fan Li, PhD, Department of Biostatistics, Yale School of Public Health, New Haven CT, 06510, USA,
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11
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Hadjistavropoulos H, Peynenburg V, Thiessen D, Nugent M, Karin E, Dear B, Titov N. A randomized factorial trial of internet-delivered cognitive behavioural therapy: An 8-week program with or without extended support and booster lesson. Internet Interv 2022; 27:100499. [PMID: 35198410 PMCID: PMC8844810 DOI: 10.1016/j.invent.2022.100499] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 01/29/2022] [Accepted: 02/01/2022] [Indexed: 11/25/2022] Open
Abstract
While internet-delivered cognitive behavioural therapy (ICBT) is effective, some patients suggest extended support post-treatment could improve care. In this randomized factorial trial, we examined the benefits of an 8-week therapist-assisted ICBT program offered with or without an optional 4-week extension of support (Factor 1) and with or without an optional booster lesson (Factor 2). Patients screened for ICBT for depression and/or anxiety were randomly assigned to the conditions (N = 434) and we examined the use of the extension and booster, differences between those who did or did not use extension or booster, and the impact of the extension or booster on outcomes, engagement, and satisfaction at 26-weeks post-enrollment. Therapists recorded time and observations with offering support during the extension and booster. In the extension group, 54.4% (n = 56) requested the extension, while in the booster group 50.9% (n = 56) accessed the booster, and in the combined group, 41.6% (n = 47) requested the extension and 51.3% (n = 58) accessed the booster. Those who requested the extension were older, and more likely to report medication and mental health service use and severe mental health-related disability at pre-treatment; they also reported putting less effort into ICBT and finding skills more difficult. The booster was more often used among those with lower symptom severity, and those who put more effort into and had more positive experiences with ICBT. As expected, those assigned to extension sent more messages to their therapist, and those assigned to booster logged in more often. Therapists also took more time to deliver ICBT with an extension (>18 min) or booster (>13 min) compared to the 8-week program, and perceived extension and booster as beneficial for some, but not all patients. Treatment satisfaction was high across conditions, and effect sizes were large from pre-treatment to 26-week follow-up on most measures. No significant group differences were found in this study. Lack of group differences, however, could reflect low use of the extension and booster. Results provide helpful information about the demand for extensions and boosters, and provide directions for future research.
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Affiliation(s)
- H.D. Hadjistavropoulos
- 3737 Wascana Parkway, Department of Psychology, University of Regina, Regina, SK S4S 0A2, Canada,Corresponding author.
| | - V. Peynenburg
- 3737 Wascana Parkway, Department of Psychology, University of Regina, Regina, SK S4S 0A2, Canada
| | - D.L. Thiessen
- 3737 Wascana Parkway, Department of Mathematics & Statistics, University of Regina, Regina, SK S4S 0A2, Canada
| | - M. Nugent
- 3737 Wascana Parkway, Department of Psychology, University of Regina, Regina, SK S4S 0A2, Canada
| | - E. Karin
- eCentreClinic, Department of Psychology, Macquarie University, Sydney, NSW 2109, Australia
| | - B.F. Dear
- eCentreClinic, Department of Psychology, Macquarie University, Sydney, NSW 2109, Australia
| | - N. Titov
- MindSpot Clinic, Australian Hearing Hub Building, eCentreClinic, Department of Psychology, Macquarie University, Sydney, NSW 2109, Australia
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12
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Alfonso F, de la Torre Hernández JM, Ibáñez B, Sabaté M, Pan M, Gulati R, Saw J, Angiolillo DJ, Adlam D, Sánchez-Madrid F. Rationale and design of the BA-SCAD (Beta-blockers and Antiplatelet agents in patients with Spontaneous Coronary Artery Dissection) randomized clinical trial. ACTA ACUST UNITED AC 2021; 75:515-522. [PMID: 34561195 DOI: 10.1016/j.rec.2021.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 08/04/2021] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Y OBJECTIVES Spontaneous coronary artery dissection (SCAD) is a rare cause of acute coronary syndrome. Most patients are empirically treated with beta-blockers and antiplatelet drugs. The Beta-blockers and Antiplatelet agents in patients with Spontaneous Coronary Artery Dissection (BA-SCAD) is an academic, pragmatic, prospective, randomized, open-label, blinded-endpoint clinical trial, performed under the auspices of the Spanish Society of Cardiology, to assess the efficacy of pharmacological therapy in patients with SCAD. METHODS Using a 2 x 2 factorial design, 600 patients will be randomized (1:1/1:1) to: a) beta-blockers (yes/no) and b) "short" (1 month) vs "prolonged" (12 months) antiplatelet therapy. Only patients with preserved left ventricular ejection fraction will be randomized to beta-blockers (yes/no) because patients with reduced left ventricular ejection fraction will receive beta-blockers according to current guidelines. Similarly, only conservatively managed patients (ie, no coronary intervention) will be randomized to the antiplatelet stratum, as patients requiring coronary interventions will receive 1-year dual antiplatelet therapy. The primary efficacy endpoint includes a composite of death, myocardial infarction, stroke, coronary revascularization, recurrent SCAD, and unplanned hospitalization for acute coronary syndrome or heart failure at 1 year. The primary safety endpoint will be bleeding. All patients will be clinically followed up yearly. A comprehensive set of additional substudies (clinical, imaging, revascularization, biomarkers, inflammatory, immunologic, pharmacogenetics, and genetic) will be conducted to ensure a holistic view of this unique and challenging clinical entity. CONCLUSIONS The results of the BA-SCAD randomized clinical trial will advance our knowledge in the treatment of patients with SCAD. The study was registered at ClinicalTrials.gov (Identifier: NCT04850417).
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Affiliation(s)
- Fernando Alfonso
- Departamento de Cardiología, Hospital Universitario de La Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Universidad Autónoma de Madrid, Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Spain.
| | | | - Borja Ibáñez
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Spain; Departamento de Cardiología, IIS-Fundación Jiménez Díaz, Centro Nacional Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Manel Sabaté
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Spain; Departamento de Cardiología, Instituto Cardiovascular, Hospital Clínic, IDIBAPS, Barcelona, Spain
| | - Manuel Pan
- Departamento de Cardiología, Hospital Universitario Reina Sofía, Universidad de Córdoba, IMIBIC, Córdoba, Spain
| | - Rajiv Gulati
- Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, United States
| | - Jacqueline Saw
- Division of Cardiology, Vancouver General Hospital, University of British Columbia, Vancouver, BC, Canada
| | - Dominick J Angiolillo
- Division of Cardiology, University of Florida College of Medicine, Jacksonville, Florida, United States
| | - David Adlam
- Department of Cardiovascular Sciences and National Institute for Health Research, Leicester Biomedical Research Centre, Glenfield Hospital, United Kingdom
| | - Francisco Sánchez-Madrid
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Spain; Departamento de Inmunología, Hospital Universitario de La Princesa, Instituto de Investigación Sanitaria Princesa (IIS-IP), Universidad Autónoma de Madrid, Madrid, Spain
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13
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Hadjistavropoulos H, Peynenburg V, Thiessen D, Nugent M, Adlam K, Owens K, Karin E, Dear B, Titov N. A pragmatic factorial randomized controlled trial of transdiagnostic internet-delivered cognitive behavioural therapy: Exploring benefits of homework reflection questionnaires and twice-weekly therapist support. Internet Interv 2020; 22:100357. [PMID: 33335846 PMCID: PMC7734229 DOI: 10.1016/j.invent.2020.100357] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/14/2020] [Accepted: 11/04/2020] [Indexed: 12/26/2022] Open
Abstract
With the growing demand for internet-delivered cognitive behavioural therapy (iCBT), this pragmatic factorial (2 × 2 × 2) randomized controlled trial evaluated strategies for facilitating iCBT engagement and outcomes in routine care. Specifically, the benefits to patients and therapists of using homework reflection questionnaires and offering patients twice-weekly therapist support were examined. Patients (n = 632) accepted into iCBT for depression and/or anxiety were randomly assigned to complete homework reflection questionnaires or not (factor 1), receive once- or twice-weekly support (factor 2), and to receive care from therapists employed in one of two settings (iCBT clinic or a community mental health clinic; factor 3). Outcomes were measured at pre-treatment, and 8, 12, and 24-weeks post-enrollment. Therapist time was tracked and a focus group was conducted to examine therapist experiences. No differences in patient outcomes were found between therapists employed in the two settings; as such, these two groups were combined for further analyses. In terms of engagement, homework reflection questionnaires were associated with fewer website log-ins and days accessing iCBT; twice-weekly support was associated with more patient emails sent to therapists. Despite engagement differences, homework reflection questionnaires and twice-weekly support did not significantly impact primary outcomes; all groups showed large improvements in depression and anxiety that were maintained at 24-week follow-up. Therapists perceived a number of benefits and challenges associated with responding to homework reflection questionnaires and offering twice-weekly support; most notably the strategies did not benefit all patients. Twice-weekly support was associated with increased therapist time and organizational challenges. It is concluded that neither completion of homework questionnaires nor offering twice-weekly support significantly improve iCBT in routine care.
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Affiliation(s)
- H.D. Hadjistavropoulos
- Department of Psychology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada,Corresponding author.
| | - V. Peynenburg
- Department of Psychology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - D.L. Thiessen
- Department of Mathematics & Statistics, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - M. Nugent
- Department of Psychology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - K. Adlam
- Department of Psychology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - K.M.B. Owens
- Adult Therapy Program, Regina Mental Health Clinic, Saskatchewan Health Authority, 2110 Hamilton St, Regina, SK S4P 2E3, Canada
| | - E. Karin
- eCentreClinic, Department of Psychology, Macquarie University, Sydney, NSW 2109, Australia
| | - B.F. Dear
- eCentreClinic, Department of Psychology, Macquarie University, Sydney, NSW 2109, Australia
| | - N. Titov
- MindSpot Clinic, eCentreClinic, Department of Psychology, Macquarie University, Australian Hearing Hub Building, Sydney, NSW 2109, Australia
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14
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Marshall ASJ, Sadarangani M, Scrivens A, Williams R, Yong J, Bowler U, Linsell L, Chiocchia V, Bell JL, Stokes C, Santhanadass P, Adams E, Juszczak E, Roehr CC. Study protocol: NeoCLEAR: Neonatal Champagne Lumbar punctures Every time - An RCT: a multicentre, randomised controlled 2 × 2 factorial trial to investigate techniques to increase lumbar puncture success. BMC Pediatr 2020; 20:165. [PMID: 32295554 PMCID: PMC7160994 DOI: 10.1186/s12887-020-02050-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 03/25/2020] [Indexed: 11/14/2022] Open
Abstract
Background The neonatal period carries the highest risk of bacterial meningitis (~ 1 in 5000 births), bearing high mortality (~ 10%) and morbidity (20–50%) rates. Lumbar puncture (LP) remains essential to the diagnosis of meningitis. Though LP is a common procedure in neonates, success rates are lower (50–60%) than in other patient populations. None of the currently-practised neonatal LP techniques are supported by evidence from adequately-powered, randomised controlled trials (RCTs). NeoCLEAR aims to compare two modifications to the traditional technique which are free, accessible, and commonly practised: sitting (as opposed to lying) position, and ‘early’ (as opposed to ‘late’) stylet removal. Methods/design Written parental informed consent permitting, infants in neonatal/maternity wards, of 27+ 0 to 44+ 0 weeks corrected gestational age and weighing ≥1000 g, who require an LP, will be randomly allocated to sitting or lying position, and to early or late stylet removal. The co-primary objectives are to compare success rates (the proportion of infants with cerebrospinal fluid red cell count < 10,000/mm3 on first LP procedure) in 1020 infants between the two positions, and between the two methods of stylet removal. Secondary outcomes relate to LP procedures, complications, diagnoses of meningitis, duration of antibiotics and hospital stay. A modified intention-to-treat analysis will be conducted. Discussion Two modifications to the traditional LP technique (sitting vs lying position; and early vs late stylet removal) will be simultaneously investigated in an efficient and appropriately-powered 2 × 2 factorial RCT design. Analysis will identify the optimal techniques (in terms of obtaining easily-interpretable cerebrospinal fluid), as well as the impact on infants, parents and healthcare systems whilst providing robust safety data. Using a pragmatic RCT design, all practitioners will be trained in all LP techniques, but there will inevitably be variation between unit practice guidelines and other aspects of individual care. An improved LP technique would result in: • Fewer uninterpretable samples, repeated attempts and procedures • Reduced distress for infants and families • Decreased antibiotic use and risk of antibiotic resistance • Reduced healthcare costs due to fewer procedures, reduced length of stay, shorter antibiotic courses, and minimised antibiotic-associated complications Trial registration ISRCTN14040914. Date assigned: 26/06/2018.
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Affiliation(s)
- Andrew S J Marshall
- Department of Paediatrics, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU, UK.
| | - Manish Sadarangani
- Vaccine Evaluation Center, BC Children's Hospital Research Institute, Vancouver, BC, V5Z 4H4, Canada.,Department of Pediatrics, University of British Columbia, 4480 Oak St, Vancouver, BC, V6H 0B3, Canada
| | - Alexandra Scrivens
- Newborn Care Unit, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU, UK.,National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Rachel Williams
- National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Jean Yong
- Newborn Care Unit, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU, UK
| | - Ursula Bowler
- National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Louise Linsell
- National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Virginia Chiocchia
- National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Jennifer L Bell
- National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Caz Stokes
- Support for the Sick Newborn And their Parents (SSNAP) Charity, Level 2, The Women's Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Patricia Santhanadass
- Support for the Sick Newborn And their Parents (SSNAP) Charity, Level 2, The Women's Centre, John Radcliffe Hospital, Oxford, OX3 9DU, UK
| | - Eleri Adams
- Newborn Care Unit, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU, UK
| | - Edmund Juszczak
- National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Charles C Roehr
- Newborn Care Unit, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Headley Way, Headington, Oxford, OX3 9DU, UK.,National Perinatal Epidemiology Unit (NPEU) Clinical Trials Unit, Nuffield Department of Population Health, University of Oxford, Old Road Campus, Headington, Oxford, OX3 7LF, UK
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Harvin JA, Zarzaur BL, Nirula R, King BT, Malhotra AK. Alternative clinical trial designs. Trauma Surg Acute Care Open 2020; 5:e000420. [PMID: 32154379 PMCID: PMC7046952 DOI: 10.1136/tsaco-2019-000420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 12/03/2019] [Indexed: 01/19/2023] Open
Abstract
High-quality clinical trials are needed to advance the care of injured patients. Traditional randomized clinical trials in trauma have challenges in generating new knowledge due to many issues, including logistical difficulties performing individual randomization, unclear pretrial estimates of treatment effect leading to often unpowered studies, and difficulty assessing the generalizability of an intervention given the heterogeneity of both patients and trauma centers. In this review, we discuss alternative clinical trial designs that can address some of these difficulties. These include pragmatic trials, cluster randomization, cluster randomized stepped wedge designs, factorial trials, and adaptive designs. Additionally, we discuss how Bayesian methods of inference may provide more knowledge to trauma and acute care surgeons compared with traditional, frequentist methods.
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Affiliation(s)
- John A Harvin
- Surgery, University of Texas McGovern Medical School, Houston, Texas, USA
| | - Ben L Zarzaur
- Surgery, University of Wisconsin Madison School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Raminder Nirula
- Surgery, University of Utah School of Medicine, Salt Lake City, Utah, USA
| | - Benjamin T King
- Neurology, University of Texas at Austin Dell Medical School, Austin, Texas, USA
| | - Ajai K Malhotra
- Surgery, University of Vermont Medical Center, Burlington, Vermont, USA
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