[amelia] Multiple imputaton question/ coding issue

Dear all, I am using Amelia II to impute but I have a question regarding one of my variables which seems to pose a problem for multiple imputation unless I can find a better coding rule: I want to control for **compliance with treatment*** (binary variable 1,0) but I am not sure how to deal with the following: say patient1 is under T1 in 1990 and complies, then dummy for T1=1 and dummy for compliance=1 say patient2 is under T1 in 1999 and does not comply, then dummy for T1=1 and dummy for compliance=0 But, then, say patient1 is NOT under T1 in 1980 (T1=0) what value should I assign to compliance in this case? Should I leave it as a missing -no value- (it makes sense but I will lose many observations). On the other hand, it doesnt' make sense to assign 1 or 0 to compliance if there was nothing to comply (or fail to comply) with in the first place. Moreover, if I leave the compliance value as missing in this case, when I use Amelia II the missing value for compliance will be imputed and I am not sure this would be correct given that in reality compliance did not exist b/c there was no treatment to comply with. Thanks in advance, Regards, Helen A. Brown - Amelia mailing list served by Harvard-MIT Data Center [Un]Subscribe/View Archive: http://lists.gking.harvard.edu/?info=amelia More info about Amelia: http://gking.harvard.edu/amelia