Epidemiological Studies of Adverse Drug Reactions

Abstract

The investigations illustrate several general principles pertinent to a discussion of epidemiology in the hospital. Adverse drug reactions represent another noninfectious disease problem amenable to study using epidemiologic methods, thus broadening the scope of the duties of the hospital epidemiologist. Patients are given many drugs when hospitalized, and at least 15% develop adverse reactions, ranging from incidental to fatal ones. The characteristics of those patients suffering adverse reactions can be identified. Various methods for surveillance of adverse drug reactions have been used. Although each method has certain deficiencies, all can provide useful information. Surveillance of drug reactions providing uniformity of reporting and satisfactory detection can best be accomplished by one or a few particularly interested physicians. Detailed study of persons given specific drugs to detect any clinical phenomenon, even though apparently unassociated with the drug given, is necessary. The method most applicable to surveillance of the general problem of adverse reactions in hospitals requires detailed, individual, daily examination of large numbers of patients. In this way, adverse reactions to many drugs can be surveyed in several hospitals simultaneously. If complete clinical and drug usage data are available, the incidence of both adverse reactions and factors predisposing patients to them can be determined rapidly and accurately.