Data monitoring (and safety) committees--what are they and why do we need them? Primary Care Alliance for Clinical Trials (PACT) Network.

A data monitoring committee (DMC) is an independent body that oversees the conduct of a randomised controlled trial. Based on the results of interim analyses of trial data and other considerations such as adverse events and previous knowledge about the treatment; the DMC makes recommendations to the researchers about the continuation of the trial. Statistical methods are applied to interim results in an attempt to ensure that false positive statistically significant results do not unduly influence the decision of whether to continue the trial. While balancing the ethical requirements of the trial, the question for the DMC is how much evidence is needed to convince regulators, scientists, doctors and patients that a treatment is effective or not effective. (non-author abstract)