Fig. 2From: Estimating relative risks in multicenter studies with a small number of centers — which methods to use? A simulation studyRoot mean square error of β1 for scenarios under randomized controlled trial study designs (a–c) and observational study designs (d–f) based on 1000 simulations for each scenario. All scenarios used a β1 of log(1.5), a control outcome rate of 15%, and an intracluster correlation coefficient of 0.08. GEE Generalized estimating equation, GLM-Bin Log-binomial regression model, GLMM Generalized linear mixed modelBack to article page