The Importance of Cluster Crossover Trials

There's a critical point that I'd like to emphasize about this study design. In each of these treatment periods where the ICU is allocated to either A, B or C there will be some noise. And so if the noise balances perfectly then a cluster crossover trial basically provides you with the same amount of power as an individual patient randomized controlled trial. But changing from 99 crossovers to 100 makes virtually no difference at all.