how to add confounding variable
I am working with a multi level data. Data is attached.In this dataset, I have 8- X variable: cumulative risk (continuous), all other risk (dichotomous). 3- Y variables: insurance and practice (dichotomous) and time (continuous)I have one confounding variable Age (continuous). I will have to add random effect to X variable. But I am confused how to add confounding variable to this analysis. Can an...