Aspects of clinic monitoring in large-scale multiclinic trials.

Monitoring the implementation of large-scale and the adherence of clinical centers to a common protocol should be an integral part of the study design and a primary responsibility of the coordinating center for the study. There are four basic concepts in external clinic monitoring: (1) the maintenance of open lines of communication between all study facilities, (2) "responsibility and accountability" for study implementation and for the integrity of the data, (3) evaluation of clinic operations, and (4) analysis of data quality. A monitoring scheme consisting of regular telephone calls to the screening centers. periodic visits to the screening centers, and continuing review of the data collected can be effectively used by the coordinating center.