Clinical experience may affect clinician compliance with assigned treatment in randomized trials

Objective: To examine the relationship between clinical experience and clinician compliance with the study protocol in randomized clinical trials.

Study design and setting: A recent randomized trial of surgical techniques for tibial fracture fixation. We consider rates of treatment crossovers and other noncompliance as a function of the relevant experience of the surgeon. We also examined the effects of noncompliance on patient outcomes.

Results: Crossovers from assigned treatment to the alternative occurred much more frequently in one arm than the other. The impact of surgical experience on crossovers was less clear, although there was some evidence that noncompliance with more difficult surgery was more frequent for less experienced surgeons. This raises the possibility that experience may be an important factor in other scenarios, affecting both compliance and patient outcomes.

Conclusion: In randomized clinical trials, noncompliance by clinicians with the randomly assigned treatment can be highly detrimental to the power of the study. Further research is needed in this area to identify, quantify, and understand the factors associated with noncompliance, including clinical experience.