From: The use of randomisation-based efficacy estimators in non-inferiority trials
The Colitis Once Daily Asacol (CODA) trial |
ivregress 2sls < <Outcome> > (<<Adherence indicator> > = < <Trial arm indicator>>), vce(robust) |
The Zoledronate versus Ibandronate Comparative Evaluation (ZICE) trial |
ivregress 2sls < <Outcome> > <<Predictors of outcome> > <<Predictors of adherence> > (<<Adherence in experimental arm> > <<Adherence in standard treatment arm> > = < <Trial arm indicator> > <<Predictors of outcome> > <<Trial arm * Predictors of outcome interactions> > <<Predictors of adherence> > <<Trial arm * Predictors of adherence interaction>>), vce(robust) |
lincom[<<Experimental treatment arm effect> > - < <Standard treatment arm effect>>] |
For the CODA trial, the adherence indicator was one variable that was 1 if the participant was allocated to the OD arm (experimental intervention) and adhered, 0 if they were allocated to the OD arm and did not adhere, and also 0 if they were allocated to the TDS arm (standard care). |
For the ZICE trial, as distinct causal parameters were identifiable, each arm had its own variable to denote adherence. This variable was 1 if the participant was allocated to the arm and adhered, 0 if they were allocated to the arm and did not adhere, and 0 if they were allocated to the other arm. |