On estimating treatment effects under non-compliance in randomized clinical trials: are intent-to-treat or instrumental variables analyses perfect solutions?

Stat Med. 2007 Feb 28;26(5):954-64. doi: 10.1002/sim.2663.


In this report, we compared four estimators (intent-to-treat, as treated, per protocol, and instrumental variables estimators) that are conventionally considered for treatment effect estimation by simulation under different non-compliance scenarios in typical clinical trial settings. We found that intent-to-treat and instrumental variables estimators are not perfect and can be problematic in some situations although these two estimators carry desirable properties as we assume.

MeSH terms

  • Humans
  • Patient Compliance / statistics & numerical data*
  • Randomized Controlled Trials as Topic*
  • Treatment Outcome
  • United States