Strengths and weaknesses of a stepped wedge cluster randomized design : its application in a colorectal cancer follow-up study

Objectives. To determine the advantages and disadvantages of a stepped wedge design for a specific clinical application. Study Design and Setting. 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. Conclusion. 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. Keywords: Stepped wedge design; Clinical trial; Cluster analysis; Colorectal cancer; Epidemiological research design; Randomized controlled tria