Table 1 Setup for simulation study for parameter values except interaction along with the number of clusters, time points, and cluster size
Value for parameter | Reason for determining value |
|---|---|
\({\theta }_{0}={\text{log}}\left(0.15/0.85\right)\) | the true log odds ratio of the outcome in the control group (\({W}_{ijk}=0\)) with reference group for binary covariate (\({X}_{ijk}=0\)) for kth individual in ith cluster at jth period. We assume that prevalence of outcome is 15% |
\({\gamma }_{1}=0, {\gamma }_{2}=0.1,{\gamma }_{3}=0.2,{\gamma }_{4}=0.3,{\gamma }_{5}=0.4\) | Increasing secular trend |
\({{\theta }_{1}={\text{log}}\left(1.35\right); \theta }_{1}={\text{log}}\left(1.68\right)\) | Chosen arbitrarily for small and intermediate effect size for intervention effect |
30%, 50% | Prevalence rate for binary covariate |
\({\theta }_{2}={\text{log}}\left(1.5\right)\) | Chosen arbitrarily for intermediate effect size for binary covariate |
\({\theta }_{3}={\text{log}}\left(1.5\right); {\theta }_{3}={\text{log}}\left(2\right)\) | Chosen arbitrarily for intermediate and large effect size for interaction |
\(I=8, 20, 40\) | Number of clusters |
\(J=5\) | Number of time steps |
\(m=\mathrm{20,40}, 60, \mathrm{80,120}\) | Cluster size |
\(ICC=0.1\) \(ICC=0.1\);\(CAC= 0.8\) | For a simple exchangeable correlation structure For a nested exchangeable correlation structure |