I'm working on a regression analysis which involves eight symptom domains comprised of individual survey items. As is the procedure in my lab, the domain scores are simple averages of the corresponding items.
I started with a stepwise logistic regression procedure to determine which domains best predicted my binary outcome. If a domain was found to be statistically associated with my outcome, I tested the corresponding individual items in a similar stepwise process to determine which items were "driving" the observed associations in the domain regression.
My question is this - are folks aware of any statistical references or research that I could cite which would support this sort of drill-down model building process?