I have two explanatory variables
A, B and two potential confounders
M, N that I also want to check for interactions. So, my covariates are
A, B, M, N, A*M, A*N, B*M, B*N
Logistic Regression with Backward Wald preserved
M, A*M, B*N. A stats friend said he didn't like to report interactions alone in the model, so suggestion I introduce N into the model and run LR again with just
M, N, A*M, B*N and no variable selection.
What is the reasoning behind this? I had significance for B*N but when I add N to the model, I lose significance, so not sure how to report this?