The stepped wedge cluster randomized trial always requires fewer clusters but not always fewer measurements, that is, participants than a parallel cluster randomized trial in a cross-sectional design. In reply

Affiliations

¹ Department for Health Evidence 133, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: E.deHoop@ebh.umcn.nl.

Comment

Esther de Hoop et al. J Clin Epidemiol. 2013 Dec.

. 2013 Dec;66(12):1428.

doi: 10.1016/j.jclinepi.2013.07.008. Epub 2013 Sep 8.

¹ Department for Health Evidence 133, Radboud University Medical Centre, PO Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: E.deHoop@ebh.umcn.nl.

No abstract available

Comment in

"Cross-sectional" stepped wedge designs always reduce the required sample size when there is no time effect.
Zhou X, Liao X, Spiegelman D. Zhou X, et al. J Clin Epidemiol. 2017 Mar;83:108-109. doi: 10.1016/j.jclinepi.2016.12.011. Epub 2017 Jan 16. J Clin Epidemiol. 2017. PMID: 28093263 Free PMC article. No abstract available.

Stepped wedge designs could reduce the required sample size in cluster randomized trials.
Woertman W, de Hoop E, Moerbeek M, Zuidema SU, Gerritsen DL, Teerenstra S. Woertman W, et al. J Clin Epidemiol. 2013 Jul;66(7):752-8. doi: 10.1016/j.jclinepi.2013.01.009. Epub 2013 Mar 22. J Clin Epidemiol. 2013. PMID: 23523551
The efficiency of stepped wedge vs. cluster randomized trials: stepped wedge studies do not always require a smaller sample size.
Hemming K, Girling A. Hemming K, et al. J Clin Epidemiol. 2013 Dec;66(12):1427-8. doi: 10.1016/j.jclinepi.2013.07.007. Epub 2013 Sep 10. J Clin Epidemiol. 2013. PMID: 24035495 No abstract available.