Purpose: The effects of attitude and subjective norm were investigated on physicians' intention to use seven drug information sources: the PDR, medical textbooks, medical journals/newsletters, pharmaceutical manufacturers' literature, pharmaceutical manufacturers' representatives, other physicians, and pharmacists. The effects of past behavior and practice characteristics were also examined.
Methods: An eight-page mail questionnaire queried health maintenance organization physicians on their intention to use, attitude (emotional response) and subjective norm (colleagues' approval/disapproval) toward use of each source when searching for drug information on a fictitious, new H2 antagonist agent.
Results: Responses were received from 54% (108) of the 200 physicians surveyed. Positive attitudes toward use had the greatest influence upon intention to use each of the sources (b > or = .40) (except for pharmacists, for which subjective norm was the most important predictor (b = .31)). Past behavior directly affected intention to use the PDR (b = .27), and pharmaceutical manufacturers' literature (b = .26). The effects of attitude and/or subjective norm on intention to use non-commercial sources of drug information were moderated by the practice characteristics.
Conclusions: These findings suggest that physicians' use of drug information sources is strongly influenced by their attitudes toward use. In addition, the importance of situational contingencies should not be overlooked when investigating the use of drug information sources.