Fig. 4From: Sample size calculation for a stepped wedge trialPower curves for a binary outcome assuming 24 clusters, each with 20 subjects. We varied the ICC and the number of randomisation crossover points. Panel (a) shows the analysis for a repeated closed cohort (cross-sectional) design, while panel (b) depicts the results for a closed cohort design (assuming individual-level ICC of 0.0016)Back to article page