Strengths and weaknesses of a stepped wedge cluster randomized design: its application in a colorectal cancer follow-up study.
OBJECTIVE
To determine the advantages and disadvantages of a stepped wedge design for a specific clinical application.


METHODS
The clinical application was a pragmatic cluster randomized surgical trial intending to find an increased percentage of curable recurrences in patients in follow-up after colorectal cancer. Advantages and disadvantages of the stepped wedge design were evaluated, and for this application, new advantages and disadvantages were presented.


RESULTS
A main advantage of the stepped wedge design was that the intervention rolls out to all participants, motivating patients and doctors, and a large number of patients who were included in this study. The stepped wedge design increased the complexity of the data analysis, and there were concerns regarding the informed consent procedure. The repeated measurements may bring burden to patients in terms of quality of life, satisfaction, and costs.


CONCLUSIONS
The stepped wedge design is a strong alternative for pragmatic cluster randomized trials. The known advantages hold, whereas most of the disadvantages were not applicable to this application. The main advantage was that we were able to include a large number of patients. Main disadvantages were that the informed consent procedure can be problematic and that the analysis of the data can be complex.
Department of Epidemiology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
Zhuozhao
Z
Zhan
Department of Epidemiology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
Edwin R
ER
van den Heuvel
Department of Epidemiology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
Peter M
PM
Doornbos
Department of Epidemiology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands; Department of General Practice, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
Huib
H
Burger
Department of Surgery, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
Charlotte J
CJ
Verberne
Department of Surgery, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands.
Theo
T
Wiggers
Department of Epidemiology, University Medical Center Groningen, University of Groningen, 9700 RB Groningen, The Netherlands. Electronic address: g.h.de.bock@umcg.nl.
Geertruida H
GH
de Bock
D002272:Carcinoembryonic Antigen / Q000032:analysis*; D016000:Cluster Analysis; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000601:surgery; D015340:Epidemiologic Research Design; D005500:Follow-Up Studies; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000737:chemistry / Q000175:diagnosis*; D016032:Randomized Controlled Trials as Topic / Q000379:methods* / Q000592:standards*
D002272:Carcinoembryonic Antigen
Clinical trial; Cluster analysis; Colorectal cancer; Epidemiological research design; Randomized controlled trial; Stepped wedge design