ROLE OF INDEPENDENT DATA-MONITORING COMMITTEES IN RANDOMIZED CLINICAL-TRIALS SPONSORED BY THE NATIONAL-CANCER-INSTITUTE

Purpose: To describe the rationale for independent data monitoring com mittees (DMCs) for National Cancer Institute (NCI)-sponsored phase III cooperative group clinical trials, Design: We review the necessity fo r interim monitoring of outcome delta during the course of randomized clinical trials and summarize the reasons for establishing DMCs with r equisite expertise and with appropriate independence from study invest igators, Results: The important components of the policy for cooperati ve group DMCs are described with a focus on the makeup of these bodies and on the complementary roles of study committee leadership and DMCs in protecting patient safety during the conduct of randomized clinica l trials, Conclusion: The cooperative group DMCs that are independent of the study committees and that have the requisite expertise to exami ne accumulating data and to base decisions on monitoring guidelines th at are specified in advance by the study committee provide a body able to protect patient safety, to protect the integrity of the clinical e xperiments on which patients have consented to participate, and to ass ure the public that conflicts of interest do not compromise either pat ient safety or trial integrity.