DRUG EFFECTS in man have been of increasing concern in recent years to both public health and government agencies. As a consequence of a burgeoning technology in the production and development of potent drugs and an ever increasing role by government regulatory agencies, information is needed if we are to make informed decisions regarding their safe use. It has become increasingly apparent that much of the data required must be obtained by prospective epidemiologic techniques. Until recently the administrative framework did not exist for obtaining such information; nor was any system easily available for its storage, analysis, and utilization. The availability of a sys-