ABSTRACT
It is increasingly common for randomised controlled trials to be overseen by Data Monitoring Committees (DMCs), whose main tasks are to monitor the accumulating study data to ensure the safety of participants, to review study progress and to make recommendations to the investigators, sponsors and funding agencies regarding the continuation, modification or termination of the trial. Not all trials need to have a DMC, and they are most common for trials of new investigational products such as drugs and vaccines, and where definitive evidence of efficacy and safety is needed to guide regulatory decisions or health policy. Such committees are given a variety of names, including Data Monitoring and Ethics Committee (DMEC) or Data Safety and Monitoring Board (DSMB), but we shall use the term DMC here.
