Monitoring Protocol Adherence

Data and Safety Monitoring

Section 3

Monitoring Protocol Adherence


Susan Ellenberg, PhD

Jeremy Sugarman, MD, MPH, MA

Doug Zatzick, MD


Contributing Editor

Gina Uhlenbrauck

Liz Wing, MA

It is sometimes argued that PCTs, as opposed to traditional trials, should do very little to address adherence within the trial, because adherence to an intervention can be considered a representation of how well the intervention would be implemented in the clinical setting. However, without information about adherence, it will be impossible to interpret trial results and determine whether a change (or lack of change) in outcomes was in fact due to the trial intervention.

Due to potential changes in clinical care that occur in healthcare delivery settings, monitoring for use of non-protocol interventions and the difference in adherence rates between the control and intervention arms can be an important part of the monitoring plan for ePCTs. The table below describes an example from the NIH Collaboratory Demonstration Projects.


Example of Adherence Monitoring in PCTs

Trial Adherence monitoring
ICD-Pieces The trial monitors adherence to the intervention by reporting use of some key components of the intervention, including use of angiotensin converting enzyme inhibitors/angiotensin receptor blockers, use of statins, and checking hemoglobin A1c.



Version History

December 13, 2018: Updated text as part of annual content update (changes made by L. Wing).

Published August 25, 2017


Ellenberg S, Sugarman J, Zatzick D. Data and Safety Monitoring: Monitoring Protocol Adherence. In: Rethinking Clinical Trials: A Living Textbook of Pragmatic Clinical Trials. Bethesda, MD: NIH Health Care Systems Research Collaboratory. Available at: Updated December 13, 2018. DOI: 10.28929/041.