I have a retrospective dataset that has records of the medications a patient was administered to prevent recurrence of heart attack. The goal is to determine if a particular drug or combination of drugs is better at preventing (or prolonging) the recurrence of heart attack.
My plan is to create an indicator variable for each of the drugs taken and include all possible two way interaction between the drugs in a cox regression model treating the problem as a survival analysis problem. Would this be an appropriate approach to answering the question? I'm thinking of using the interaction terms to model the effect of drug pairs. Should I create indicator variables for all pair of drug combination in the data instead and why?