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Cluster Randomized Designs in Cancer Care Delivery Research
Wednesday, May 3 - Friday, May 5, 2022
11:00 am - 5:00 pm
Overview
This short course will provide training in the design, conduct, and analysis of cluster randomized trials (CRTs), including parallel CRTs, stepped-wedge CRTs, and cluster randomized cross-over trials (CRXO). The course is jointly sponsored by NCI’s Healthcare Delivery Research Program and Implementation Science Team. CRTs are increasingly used to evaluate interventions to improve care delivery and to study strategies for implementing evidence-based interventions into routine clinical practice. They require specific methods of design and statistical analysis.
The course addresses the rationale for using these designs, specific design issues, the randomization process, sample size calculations, analytical methods, ethical considerations, practical issues in managing these trials, and trial reporting and interpretation. Principles will be illustrated using case studies of the different variations of cluster randomized trials across the cancer control continuum (prevention, diagnosis, treatment, survivorship, and at end-of-life).
This course has been designed to address the training needs of doctorally prepared cancer care delivery/implementation researchers (including statisticians and methodologists), as well as post-doctoral fellows and other trainees and other scientific team members such as project coordinators. Participants should have fundamental understanding of basic statistics, sources of bias in research designs, and the design, conduct and interpretation of individual-level randomized interventional trials in behavioural science/healthcare delivery. Some of the sessions are specifically targeted at statisticians, methodologists, and researchers with an interest in more complex statistical topics.
Intended Audience
This course has been designed to address the training needs of doctorally prepared cancer care delivery/implementation researchers (including statisticians and methodologists), as well as post-doctoral fellows and other trainees and other scientific team members such as project coordinators. Participants should have fundamental understanding of basic statistics, sources of bias in research designs, and the design, conduct and interpretation of individual-level randomized interventional trials in behavioral science/healthcare delivery. Some of the sessions are specifically targeted at statisticians, methodologists, and researchers with an interest in more complex statistical topics.
Objectives
By the end of this course, attendees will be able to critically appraise and apply a range of appropriate design approaches and analytical methods for cluster randomized trials (CRTs), including parallel CRTs, stepped-wedge CRTs, and cluster randomized cross-over trials (CRXO).
The course will cover:
- Key concepts of cluster randomized trials (also known as group-randomized trials), including the rationale for cluster randomization and measures of between-cluster variation
- Design of cluster randomized trials, including cluster selection and randomization procedures and different design variations such as the parallel CRT, the stepped-wedge CRT, and the cluster randomized cross-over design (CRXO)
- Risk of bias and justification for choosing a CRT design
- Power calculations and justification of sample size
- Analysis using both cluster-level summaries and individual-level data (random effects models and generalized estimating equations)
- Ethical considerations, data monitoring and study reporting and results dissemination
- Stakeholder perspectives on practical considerations and challenges when conducting CRTs, incorporating the diverse viewpoints of researchers, project managers, healthcare system leaders, community oncology research networks, reporting guideline developers, and journal editors
Agenda & Recordings
| Time (EDT) | Agenda |
|---|---|
| 11:00 am - 11:10 am |
Welcome and Course Overview
Greetings from NCI Senior Leadership
|
Session 1 11:10 am - 12:35 pm |
Introduction to Cluster Randomized TrialsThis session introduces the foundational elements to be considered in designing a cluster randomized trial (CRT) versus a traditional patient randomized trial. The session will introduce the audience to the key concepts and considerations for a cluster randomized trial, including the range of different types of cluster randomized designs. |
|
S1.a |
An Introduction to the Parallel Cluster Randomized TrialThis session introduces the CRT design including key features; different types of interventions (cluster-level, professional-level, individual-level); broad outcome types (differentiating implementation outcomes from clinical outcomes); and participant recruitment. (20 minutes) |
|
S1.b |
An Overview of the Statistical Implications of Cluster RandomizationThis session reviews the statistical considerations associated with cluster randomization (including intra-cluster correlation and degrees of freedom corrections for small samples) and summarizes how and when CRTs are being utilized in the current scientific literature. (21 minutes) |
|
S1.c |
An Introduction to Multiple Period Cluster Randomized Trial DesignsThis session introduces the multiple period CRT design, including the different types of multiple period CRT designs, such as parallel arm with baseline period and cluster cross-over designs. An introduction to cohort and cross-sectional sampling, and an exploration of the trade-offs between statistical efficiency and trial logistics are provided. (15 minutes) |
|
S1.d |
An Introduction to the Stepped-Wedge Cluster Randomized TrialThis session introduces the stepped-wedge cluster randomized trial (SW-CRT) design and provides an overview of the different types of SW-CRT design (cohort, cross-sectional sampling). It also describes associated methodological complexities (e.g., time confounding, longitudinal correlations, time-varying effects). (28 minutes) |
| 12:35 pm - 12:50 pm |
Question and Answer SessionModerator: Dr. Sandra Mitchell |
| 12:50 pm - 1:20 pm | Break |
Session 2 1:20 pm - 2:55 pm |
Risk of Bias and Design JustificationThis session helps researchers determine and justify a CRT design (e.g., parallel CRT, SW-CRT or other) appropriate for particular settings. Alternatives/extensions within the family of CRT designs, as well as the implications of these decisions for internal validity (risk of bias) and pragmatic considerations, are also addressed. |
|
S2.a |
Risk of Bias in Parallel Cluster Randomized TrialsThis session addresses risk of bias in parallel CRTs, as defined by the Cochrane Risk of Bias tool (RoB2.0), including strategies to prevent or mitigate bias. The prevalence of these risks in contemporary samples of CRTs is reviewed, providing illustrative examples of the most common sources of bias. (24 minutes) |
|
S2.b |
Justification for a Cluster Randomized DesignThis session addresses the justification for choosing a cluster trial design, situating that justification within the context of risk of bias; study aims related to gauging direct and indirect effects; as well as contamination; trial logistics; and unit of delivery. Concepts are illustrated with examples. The implications of post-randomization recruitment on risk of bias and how to mitigate such biases are reviewed. (20 minutes) |
|
S2.c |
Risk of Bias in Stepped-Wedge Cluster Randomized TrialsThis session addresses additional risks of bias in SW-CRTs and other multiple period designs, including consideration of secular trends, contamination, and randomization deviations. (22 minutes) |
|
S2.d |
Justification for using a Stepped-Wedge Cluster Randomized TrialThis session summarizes and provides illustrative examples of the justifications for using a stepped-wedge trial design, including social acceptability, ethical considerations, and sequential roll-out and other pragmatic/feasibility considerations. (23 minutes) |
| 2:55 pm - 3:10 pm |
Question and Answer SessionModerator: Dr. Wynne Norton |
| 3:10 pm - 3:25 pm | Break |
Session 3 3:25 pm - 4:30 pm |
Trial Implementation and RandomizationThis session will help researchers identify common practical trial implementation issues that might need to be surmounted/avoided when conducting a cluster randomized trial (including parallel designs, stepped-wedge, and cluster cross-over designs). The session will also cover the pros and cons of different randomization methods. |
|
S3.a |
Practical Design-Based Considerations in Cluster Randomized TrialsPractical issues in the design of CRTs are addressed in this session, including the choice of cluster, transition periods, staggered starts, staircase designs, number of sequences, duration of study and the implications when using a parallel design, stepped-wedge design, or cluster cross-over design. The importance of hybrid and pilot studies are highlighted. (31 minutes) |
|
S3.b |
Randomization Methods in Cluster Randomized TrialsThis session provides an overview of different types of restricted randomization in cluster trials (simple, stratified, paired, covariate constrained, minimization), including their comparative benefits (including variations that allow you to stagger the cluster starts); the importance of design-based adjustment; and implementation of randomization methods. (21 minutes) |
| 4:30 pm - 5:00 pm |
Question and Answer SessionModerator: Dr. Sandra Mitchell |
| 5:00 pm |
Wrap Up and Planning for Day 2Dr. Sandra Mitchell and Dr. Wynne Norton |
| Time (EDT) | Agenda |
|---|---|
| 11:00 am - 11:05 am |
Welcome to Day 2Dr. Sandra Mitchell, Dr. Wynne Norton |
Session 4 11:05 am - 1:05 pm |
Sample Size and Statistical EfficiencyThis session will allow researchers to design cluster randomized trials to maximize statistical efficiency, given the constraints of the setting. Some of these sessions are designed for methodologists and statisticians and will review methods for sample size estimation in CRTs, including the importance of the consideration of non-exchangeable correlation structures. |
|
S4.a |
Statistically Efficient Cluster Randomized DesignsThis session addresses considerations for statistically efficient cluster trial designs including optimal choice of cluster size, number of clusters, number of crossovers, for parallel, stepped-wedge and cross-over designs. (28 minutes) |
|
S4.b |
Sample Size Determination in Parallel Arm Cluster Randomized TrialsThis session reviews sample size calculations for parallel CRTs (including trials with continuous outcomes, binary outcomes, varying cluster sizes, intra-cluster correlations, small sample corrections). Concepts are illustrated with worked examples and practical resources, including implementation tools and sources for estimating the intra-cluster correlation, including rules of thumb. (32 minutes) |
|
S4.c |
Sample Size Determination for Multiple Period Cluster Randomized TrialsThis session reviews sample size calculations for SW-CRTs and other multiple period CRT designs. The importance of non-exchangeable correlation structures, including cohort or cross-sectional designs, incomplete designs, conditional vs. marginal models, immediate vs. gradual treatment effects, different analytical approximations for non-continuous outcomes, magnitude of time effects, unequal cluster sizes, unequal allocation, cluster-treatment effect heterogeneity are addressed. (56 minutes) |
| 1:05 pm - 1:20 pm |
Question and Answer SessionModerator: Dr. Wynne Norton |
| 1:20 pm - 1:50 pm | Break |
Session 4 (continued) 1:50 pm - 2:50 pm |
Sample Size and Statistical Efficiency (continued) |
|
S4.d |
Practical Trial Implementation: Sample Size Calculation for Multiple Period Cluster Randomized Trial DesignsThis session focuses on selection of a sample size calculator that supports different design features and illustrates sample size implications of different design features. Sample size calculation implemented using a variety of software platforms is demonstrated. (57 minutes) |
| 2:50 pm - 3:05 pm |
Question and Answer SessionModerator: Dr. Wynne Norton |
Session 5 3:05 pm - 4:50 pm |
Analysis of Parallel Cluster Randomized TrialsThis technical session is targeted to methodologists and statisticians, providing an in-depth treatment of the analysis of parallel CRTs, including model specification. |
|
S5.a |
Estimands: Thinking Carefully About What We Are Trying to EstimateThis session introduces basic considerations for analyzing CRTs, including specification of primary and secondary outcomes and the estimand of interest, intention to treat, covariate adjustment, and analysis such as odds ratios, relative risks, risk differences, and marginal vs conditional effects. (48 minutes) |
|
S5.b |
Analysis of Parallel Arm Cluster Randomized TrialsThis session presents methods of analysis for parallel arm CRTs (continuous and binary outcomes; cluster-level methods, mixed models, generalized estimating equations), including practical applications. The session highlights the importance of small sample corrections and alternatives for estimating risk differences and relative risks (marginal standardization and modified Poisson). (51 minutes) |
| 4:50 pm - 5:00 pm |
Question and Answer SessionModerator: Dr. Sandra Mitchell |
| 5:00 pm |
Wrap Up and Planning for Day 3Dr. Sandra Mitchell and Dr. Wynne Norton |
| Time (EDT) | Agenda |
|---|---|
| 11:00 am - 11:05 am |
Welcome to Day 3Dr. Sandra Mitchell, Dr. Wynne Norton |
Session 5 (continued) 11:05 am - 11:30 am |
Analysis of Parallel Cluster Randomized Trials (continued) |
|
S5.c |
Small Sample Corrections in the Analysis of Parallel Cluster Randomized TrialsThis session addresses small sample corrections in parallel CRTs (between-within, Kenward-Roger, Fay-Graubard, KC, etc.) and their comparative performance; and the use of randomization-based tests. (21 minutes) |
Session 6 11:30 am - 12:20 pm |
Analysis of Cluster Randomized TrialsThis technical session is targeted to methodologists and statisticians, providing an in-depth treatment of the analysis of longitudinal cluster randomized trials, including model specification. |
|
S6.a |
Methods of Analysis for Stepped-Wedge Cluster Randomized TrialsThis session focuses on mixed-effects regression for continuous outcomes accounting for complex correlation structures. Sample syntax for analysis in SAS, R and STATA is provided. The implications of misspecification of the correlation structure in the analysis are addressed. (45 minutes) |
| 12:20 pm - 12:35 pm |
Question and Answer SessionModerator: Dr. Sandra Mitchell |
Session 6 (continued) 12:35 pm - 1:15 pm |
Analysis of Cluster Randomized Trials (continued) |
|
S6.b |
Advanced Methods of Analysis for Stepped-Wedge Cluster Randomized TrialsThis session addresses advanced methods of analysis for SW-CRTs including methods for binary outcomes and various extensions of mixed-effects regression to accommodate deviations from model assumptions (e.g., time-varying treatment effects and cluster-treatment effect heterogeneity). Alternatives to mixed effects regression are introduced. (37 minutes) |
| 1:15 pm - 1:30 pm |
Question and Answer SessionModerator: Dr. Wynne Norton |
| 1:30 pm - 2:00 pm | Break |
Session 6 (continued) 2:00 pm - 2:35 pm |
Analysis of Cluster Randomized Trials (continued) |
|
S6.c |
Estimation of Intra-Cluster Correlations to Inform the Design of Cluster Randomized TrialsThis session addresses the estimation of intra-cluster correlations to inform the design of parallel and multiple-period cluster trials, illustrating the concepts using Stata software. (18 minutes) |
|
S6.d |
Estimation of Intra-Cluster Correlations for Multiple Period Cluster Randomized Trials Using SASThis session addresses the estimation of intra-cluster correlations to inform the design of parallel and multiple-period cluster trials, illustrating the concepts using SAS software. (8 minutes) |
| 2:35 pm - 2:50 pm |
Question and Answer SessionModerator: Dr. Wynne Norton |
Session 7 2:50 pm - 4:30 pm |
Data Monitoring and ReportingThis session introduces researchers to the unique considerations in monitoring and reporting CRTs and summarizes the concepts of importance when critically appraising studies using these designs. This material will help researchers appropriately consider the ethical implications of their chosen study design, how and when consent should be obtained, and the importance of trial registration. |
|
S7.a |
Reporting of Cluster Randomized TrialsThis session discusses the reporting guideline extensions for CRTs and SW-CRTs. (25 minutes) |
|
S7.b |
Ethical Issues in Cluster Randomized TrialsThis session provides an overview of the Ottawa Statement on the Ethical Design and Conduct of Cluster Randomized Trials, including the importance of justifying the use of cluster randomization, identifying research participants, and addressing informed consent and human subjects protections. (33 minutes) |
|
S7.c |
Data Monitoring in Cluster Randomized TrialsThis session addresses considerations relevant to data monitoring in CRTs including interim analysis, data quality checks, tests for selection bias and sample size re-estimation. (38 minutes) |
| 4:30 pm - 4:55 pm |
Question and Answer SessionModerator: Dr. Sandra Mitchell |
| 5:00 pm |
Course Wrap UpDr. Sandra Mitchell and Dr. Wynne Norton |
Faculty
Course Co-Directors
Sandra A. Mitchell, PhD, CRNP, FAAN
sandra.mitchell@nih.gov
Sandra A. Mitchell, PhD, CRNP, FAAN is Senior Scientist and Program Director in the Outcomes Research Branch, Healthcare Delivery Research Program, Division of Cancer Control and Population Sciences at the National Cancer Institute. She directs a portfolio of research focused in several areas, including the development and testing of interventions to address symptom burden and functional impairment, and to improve self-management during and following cancer treatment. She serves as a Science Officer for the Improving the Management of symPtoms during And following Cancer Treatment (IMPACT) Consortium. Additional areas of research interest include implementation science and novel trial designs for cancer care delivery research.
Wynne E. Norton, PhD
wynne.norton@nih.gov
Wynne E. Norton, Ph.D. is a Program Director in Implementation Science in the Division of Cancer Control and Population Sciences at the National Cancer Institute. She also holds a secondary appointment in the Healthcare Delivery Research Program. Dr. Norton’s research interests include de-implementation of ineffective interventions, evidence-based cancer care delivery, and pragmatic trials of implementation strategies. Dr. Norton serves as a scientific collaborator on three NCI Cancer MoonshotSM Initiatives: Accelerating Colorectal Cancer Screening and Follow-up Through Implementation Science Consortium (ACCSIS), Improving the Management of symPtoms during And following Cancer Treatment (IMPACT) Consortium, and the Implementation Science Centers in Cancer Control (ISC3).
Course Faculty
Karla Hemming, PhD
k.Hemming@bham.ac.uk
Karla Hemming, PhD is a Professor of Biostatistics at the Institute of Applied Health Research, University of Birmingham, UK. Dr. Hemming’s research interests include how to design cluster and stepped-wedge trials so as to maximize their statistical efficiency and minimize their risk of bias; how to model time and treatment effect heterogeneity in longitudinal cluster trials; and the ethical issues surrounding these pragmatic trial designs, such as ethical oversight and consent. She has recently led the development of the CONSORT extension for the stepped-wedge cluster randomized trial.
Monica Taljaard, PhD
mtaljaard@ohri.ca
Monica Taljaard, PhD is a Senior Scientist in the Clinical Epidemiology Program at the Ottawa Hospital Research Institute (OHRI) and Professor in the School of Epidemiology and Public Health at the University of Ottawa. Having immigrated from South Africa, she received her PhD degree in Epidemiology and Biostatistics at Western University in London, Ontario, Canada, in 2006. Her research interests include the design, analysis and ethics of pragmatic and cluster randomized trials. As a methodologist with the Ottawa Methods Centre, she works with clinicians and researchers from a variety of backgrounds in the design and analysis of cluster randomized trials, standard clinical trials, and observational studies. She is Deputy Editor of Clinical Trials: Journal of the Society for Clinical Trials.
Resources
Textbooks
- Campbell, M. J., & Walters, S. J. (2014). How to design, analyse and report cluster randomised trials in medicine and health related research. John Wiley & Sons.
- Donner, A., Klar, N. (2010). Design and Analysis of Cluster Randomization Trials in Health Research. United Kingdom: Wiley.
- Eldridge, S., & Kerry, S. (2012). A practical guide to cluster randomised trials in health services research. John Wiley & Sons.
- Hayes, R. J., & Moulton, L. H. (2017). Cluster Randomised Trials. Chapman and Hall/CRC.
- Matthews, J. N. (2006). Introduction to Randomized Controlled Clinical Trials. United Kingdom: CRC Press.
- Murray, D. M. (1998). Design and Analysis of Group-randomized Trials. United Kingdom: Oxford University Press.
Websites
- Cluster Randomized Trials: Facilitating Quality Trials and Methodological Research. Queen Mary University of London.
- NIH Pragmatic Trials Collaboratory: Rethinking Clinical Trials®.
- Pragmatic and Group-Randomized Trials in Public Health and Medicine: Online Course. Office of Disease Prevention, National Institutes of Health.
- Research Methods Resources, National Institutes of Health.
Readings
| Authors | Publication Title | Journal & Citation |
|---|---|---|
| Barker, D., P. McElduff, C. D'Este, and M. J. Campbell | Stepped Wedge Cluster Randomised Trials: A Review of the Statistical Methodology Used and Available |
BMC Med Res Methodol 16 (Jun 6 2016): 69 |
| Borhan, S., A. Papaioannou, J. Ma, J. Adachi, and L. Thabane | Analysis and Reporting of Stratified Cluster Randomized Trials-a Systematic Survey |
Trials 21, no. 1 (Nov 17 2020): 930 |
| Caille, A., E. Tavernier, M. Taljaard, and S. Desmée | Methodological Review Showed That Time-to-Event Outcomes Are Often Inadequately Handled in Cluster Randomized Trials |
J Clin Epidemiol 134 (Jun 2021): 125-37 |
| Caille A, Taljaard M, Le Vilain FA, Le Moigne A, Copas AJ, Tubach F, Dechartres A | Recruitment and implementation challenges were common in stepped-wedge cluster randomized trials: results from a methodological review |
Journal of Clinical Epidemiology. In press |
| Chan, C. L., C. Leyrat, and S. M. Eldridge | Quality of Reporting of Pilot and Feasibility Cluster Randomised Trials: A Systematic Review |
BMJ Open 7, no. 11 (Nov 8 2017): e016970 |
| Cook, D. J., W. B. Rutherford, D. C. Scales, N. K. J. Adhikari, and B. H. Cuthbertson | Rationale, Methodological Quality, and Reporting of Cluster-Randomized Controlled Trials in Critical Care Medicine: A Systematic Review |
Crit Care Med 49, no. 6 (Jun 1 2021): 977-87 |
| Eichner, F. A., R. H. H. Groenwold, D. E. Grobbee, and K. Oude Rengerink | Systematic Review Showed That Stepped-Wedge Cluster Randomized Trials Often Did Not Reach Their Planned Sample Size |
J Clin Epidemiol 107 (Mar 2019): 89-100 |
| Hemming, K., K. Carroll, J. Thompson, A. Forbes, and M. Taljaard... | Quality of Stepped-Wedge Trial Reporting Can Be Reliably Assessed Using An updated Consort: Crowd-Sourcing Systematic Review |
J Clin Epidemiol 107 (Mar 2019): 77-88 |
| Jones, B. G., A. J. Streeter, A. Baker, R. Moyeed, and S. Creanor | Bayesian Statistics in the Design and Analysis of Cluster Randomised Controlled Trials and Their Reporting Quality: A Methodological Systematic Review |
Syst Rev 10, no. 1 (Mar 31 2021): 91 |
| Kristunas, C. A., K. Hemming, H. Eborall, S. Eldridge, and L. J. Gray | The Current Use of Feasibility Studies in the Assessment of Feasibility for Stepped-Wedge Cluster Randomised Trials: A Systematic Review |
BMC Med Res Methodol 19, no. 1 (Jan 10 2019): 12 |
| Kristunas, C., T. Morris, and L. Gray | Unequal Cluster Sizes in Stepped-Wedge Cluster Randomised Trials: A Systematic Review |
BMJ Open 7, no. 11 (Nov 15 2017): e017151 |
| Lung, T., L. Si, R. Hooper, and G. L. Di Tanna | Health Economic Evaluation Alongside Stepped Wedge Trials: A Methodological Systematic Review |
Pharmacoeconomics 39, no. 1 (Jan 2021): 63-80 |
| Murray, D. M., M. Taljaard, E. L. Turner, and S. M. George | Essential Ingredients and Innovations in the Design and Analysis of Group-Randomized Trials |
Annu Rev Public Health 41 (Apr 2 2020): 1-19 |
| Offorha, B. C., S. J. Walters, and R. M. Jacques | Statistical Analysis of Publicly Funded Cluster Randomised Controlled Trials: A Review of the National Institute for Health Research Journals Library |
Trials 23, no. 1 (Feb 4 2022): 115 |
| O'Hara, L. M., N. Blanco, S. Leekha, K. A. Stafford, G. P. Slobogean, E. Ludeman, and A. D. Harris | Design, Implementation, and Analysis Considerations for Cluster-Randomized Trials in Infection Control and Hospital Epidemiology: A Systematic Review |
Infect Control Hosp Epidemiol 40, no. 6 (Jun 2019): 686-92 |
| Pérez, M. C., N. Minoyan, V. Ridde, M. P. Sylvestre, and M. Johri | Comparison of Registered and Published Intervention Fidelity Assessment in Cluster Randomised Trials of Public Health Interventions in Low- and Middle-Income Countries: Systematic Review |
Trials 19, no. 1 (Jul 31 2018): 410 |
| Siebenhofer, A., M. A. Paulitsch, G. Pregartner, A. Berghold, K. Jeitler, C. Muth, and J. Engler | Cluster-Randomized Controlled Trials Evaluating Complex Interventions in General Practices Are Mostly Ineffective: A Systematic Review |
J Clin Epidemiol 94 (Feb 2018): 85-96 |
| Starks, M. A., G. D. Sanders, R. R. Coeytaux, I. L. Riley, L. R. Jackson, 2nd, A. M. Brooks, K. L. Thomas, K. R. Choudhury, R. M. Califf, and A. F. Hernandez | Assessing Heterogeneity of Treatment Effect Analyses in Health-Related Cluster Randomized Trials: A Systematic Review |
PLoS One 14, no. 8 (2019): e0219894 |
| Taljaard, M., K. Hemming, L. Shah, B. Giraudeau, J. M. Grimshaw, and C. Weijer | Inadequacy of Ethical Conduct and Reporting of Stepped Wedge Cluster Randomized Trials: Results from a Systematic Review |
Clin Trials 14, no. 4 (Aug 2017): 333-41 |
| Turner, E. L., F. Li, J. A. Gallis, M. Prague, and D. M. Murray | Review of Recent Methodological Developments in Group-Randomized Trials: Part 1-Design |
Am J Public Health 107, no. 6 (Jun 2017): 907-15 |
| Turner, E. L., M. Prague, J. A. Gallis, F. Li, and D. M. Murray | Review of Recent Methodological Developments in Group-Randomized Trials: Part 2-Analysis |
Am J Public Health 107, no. 7 (Jul 2017): 1078-86 |
| Turner, E. L., A. C. Platt, J. A. Gallis, K. Tetreault, C. Easter, J. E. McKenzie, S. Nash, A. B. Forbes, and K. Hemming | Completeness of Reporting and Risks of Overstating Impact in Cluster Randomised Trials: A Systematic Review |
Lancet Glob Health 9, no. 8 (Aug 2021): e1163-e68 |
| Wang, M., Y. Jin, Z. J. Hu, A. Thabane, B. Dennis, O. Gajic-Veljanoski, J. Paul, and L. Thabane | The Reporting Quality of Abstracts of Stepped Wedge Randomized Trials Is Suboptimal: A Systematic Survey of the Literature |
Contemp Clin Trials Commun 8 (Dec 2017): 1-10 |
| Watson, S. I., A. Girling, and K. Hemming | Design and Analysis of Three-Arm Parallel Cluster Randomized Trials with Small Numbers of Clusters |
Stat Med 40, no. 5 (Feb 28 2021): 1133-46 |
| Wolfenden, L., Foy, R., Presseau, J., Grimshaw, J.M., Ivers, N.M, Powell, B.J., Taljaard, M., Wiggers, J., Sutherland, R., Nathan, N., Williams, C.M., Kingsland, M., Milat, A., Hodder, R.K., & Yoong, S.L. | Designing and Undertaking Randomized Implementation Trials: Guide for Researchers |
BMJ (2021): 372:m3721 |
| Zhan, D., L. Xu, Y. Ouyang, R. Sawatzky, and H. Wong | Methods for Dealing with Unequal Cluster Sizes in Cluster Randomized Trials: A Scoping Review |
PLoS One 16, no. 7 (2021): e0255389 |
Web Resources For Design And Analysis Of Multiple Period Cluster Randomized Trials
Sample size calculation resources
- A shiny app to find a sample size calculator that has the features you need
- Main app-based calculators for sample size calculation:
- Other sample size calculation resources
- R and SAS code used to perform the sample size calculation for worked examples in the presentation