When should data and safety monitoring committees share interim results in cardiovascular trials?

DATA AND SAFETY MONITORING COMMITTEES (DSMCS) often are empanelled in randomized controlled trials (RCTs), especially multicenter trials, when primary end points include mortality and major morbidity. These committees periodically review safety and efficacy data and, based on their benefit-to-risk assessment, recommend to the sponsor whether the trial should continue and if so, whether modifications are necessary. Primarily, the DSMC must minimize risks to trial participants. Sponsors and investigators of RCTs help ensure external credibility by delegating oversight to an external committee. Although cultural differences may affect regional perceptions in the increasingly frequent multinational trials, external, independent DSMCs are accepted throughout the world. Appreciation of the potential utility of DSMCs and their increasing application to clinical trials has led to efforts to establish standards for their structure and function. These nonmandatory recommendations include the 2006 US Food and Drug Administration (FDA) guidance for clinical trial sponsors, the DAMOCLES study group recommendations for DSMC charters, and a comprehensive treatise by highly respected academic clinical trial statisticians. The form and function of DSMCs vary among clinical trials and sponsors. Although the goal of separating trial monitoring from day-to-day trial operations is constant, the needs of different trials and sponsors raise questions about procedures governing communication and data sharing among the DSMC, sponsors, and investigators.