Fig. 4
From: Explaining the variation in the attained power of a stepped-wedge trial with unequal cluster sizes
The probability that the attained power falls more than 5 % below the nominal (left set of panels) or the expected (right set of panels) power by CV. The risks increased as CV increased in all scenarios except the ones with 12 clusters. The risks were near zero when the CV was smaller than 0.7, except for the scenarios with 12 clusters and two size groups. Panel labels identify the total number of clusters (first line) and the distribution of clusters to the cluster size groups S:L or S:M:L (second line)