Usage of information sources by general practitioners.

Questionnaires were sent to approximately 500 general practioners in five areas of one National Health Service Region; there was a 52% response. Certain characteristics of each general practitioner, which were collected from the questionnaire and medical lists, were used to assess how information was used by different `types' of general practitioner. Generally, sources of information emanating from the pharmaceutical industry are used more to introduce the new product, while the `professional' sources such as medical journals are used more to evaluate it. Younger doctors used Drug and Therapeutics Bulletin more than did their colleagues, and single-practice doctors found the representative to be more useful than did joint-practice doctors.