Grand Rounds 2: Stepped Wedge Cluster Randomized Trials: What, How, And When?

This Grand Rounds webinar focuses on the use of stepped wedge design in cluster randomized trials (SW-CRT). SW-CRT is a novel research design embraced by clinical researchers. It is unique from conventional parallel arm CRTs in that all clusters receive the intervention. The three main types of SW-CRT designs are presented, along with common justifications for employing these designs and their implications.


Monica Taljaard, PhD

Watch the Webinar

Stepped Wedge Cluster Randomized Trials: What, How, And When? from NIA IMPACT Collaboratory on Vimeo.

Download the Presentation

Stepped Wedge Cluster Randomized Trials: What, How and When? a NIA IMPACT Collaboratory Grand Rounds presentation.


Stepped wedge cluster, SW-CRT, sample size calculation

Learning Objectives

  1. Describe the key characteristics and main types of stepped wedge cluster randomized trials (SW-CRTs) with examples.
  2. Explain the main approach to analysis and sample size calculation for SW-CRTs.
  3. Discuss what is an appropriate justification for using a SW-CRTs.

Related Articles and Resources

  1. Kasza J1, Taljaard M2,3, Forbes AB1 Information content of stepped-wedge designs when treatment effect heterogeneity and/or implementation periods are present
  2. Teerenstra S, Taljaard M, Haenen A, Huis A, Atsma F, Rodwell L, Hulscher M. Sample size calculation for stepped-wedge cluster-randomized trials with more than two levels of clustering. Clinical Trials. 2019; 16(3):225-236. doi: 10.1177/1740774519829053.
  3. R package ‘swCRTdesign’
  4. R-Shiny (Hemming & Kasza) 

Grand Rounds 1: Are you ready for a pragmatic trial? The RAPT model and implementation considerations

This Grand Rounds webinar focuses on using the Readiness Assessment for Pragmatic Trials (RAPT) model to assess an intervention’s readiness for an embedded pragmatic clinical trial (ePCT). RAPT includes nine domains that reflect a range of considerations regarding the feasibility of successfully employing pragmatic methods and the prospect of an intervention’s widespread adoption, if proven effective. Researchers using RAPT to evaluate an intervention are asked to qualitatively assess each domain from low to high readiness and can use the results to inform team discussion about when and how to proceed with an ePCT. In this session, we describe the model’s creation, domains, and scoring criteria, and then provide an example of its application to iterative phases of a pragmatic study.


Rosa Baier, MPH
Laura Gitlin, PhD, FGSA, FAAN
Eric Jutkowitz, PhD


Watch the Webinar

IMPACT Grand Rounds_RAPT Model from NIA IMPACT Collaboratory on Vimeo.


Assessment, Pragmatic Trials, Implementation, RAPT Model

Learning Objectives

  1. Understand how RAPT complements and differs from PRECIS-2
  2. Understand RAPT’s domains and their relevance for conducting an ePCT
  3. Learn how RAPT results can inform decisions about and preparation for proceeding to an ePCT
  4. Be prepared to apply RAPT to interventions and use results to guide team discussion