THE DETERMINANTS OF PHYSICIAN ATTITUDES AND SUBJECTIVE NORMS TOWARD DRUG INFORMATION-SOURCES - MODIFICATION AND TEST OF THE THEORY OF REASONED ACTION

Purpose. To improve upon the theory of reasoned action and apply it to pharmaceutical research, we investigated the effects of relevant appr aisals, attributes, and past behavior of physicians on the use of drug information sources. We also examined the moderating effects of pract ice characteristics. Methods. A mail questionnaire asked HMO physician s to evaluate seven common sources of drug information on general appr aisals (degree of usefulness and ease of use), specific attributes (av ailability, quality of information on harmful effects and on drug effi cacy), and past behavior when searching for information on a new, simu lated H-2 antagonist agent. Semantic differential scales were used to measure each appraisal, attribute and past behavior. Information was a lso collected on practice characteristics. Results. Findings from 108/ 200 respondents indicated that appraisals and attributes were useful d eterminants of attitudes and subjective norms toward use. Degree of us efulness and quality of information on harmful effects were important predictors of attitudes toward use for several sources of information. Ease of use and degree of usefulness were important predictors of sub jective norms toward use. In many cases, moderating effects of practic e characteristics were in opposing directions. Past behavior had signi ficant direct effects on attitudes toward the PDR. Conclusions. The fi ndings suggest ways to improve the usefulness of the theory of reasone d action as a model of decision-making. We also propose practical guid elines that can be used to improve the types of drug information sourc es used by physicians.