Data Monitoring in Clinical Trials..A Case Studies Approach

Monitoring of clinical trials for early evidence of benefit and harm has gotten considerable attention.1 More formal guidelines and requirements2–4 have evolved in recent years, but in fact monitoring of trials is a practice that has been going on for almost four decades.5 For trials that involved conditions 

or interventions with serious risks, such as mortality or major morbidity, the tradition and policy has been to have an independent monitoring committee to review accumulating data for evidence of harm or convincing benefit that would require modifying or terminating a trial early. During the past four

decades, many trials have had monitoring committees to assume this respon-sibility.With the new emphasis on monitoring, this type of activity is increas-ing dramatically as the number of clinical trials being conducted to evaluate new interventions for patients or participants with serious risk or serious out- comes also increases.For example,policies of the National Institutes of Health (NIH) in the United States (US) call for monitoring committees for all phase III trials.2 Guidelines of the US Food and Drug Administration suggest such committees for trials of high-risk interventions or patients at high risk.