Prescribing by canadian general practitioners: review of the english language literature.

General practitioners write the vast majority of the 190 million prescriptions issued annually in Canada. The author reviewed the English language literature to determine the general characteristics of that prescribing, the appropriateness of prescribing, and factors that influence prescribing. On average, GPs write one prescription for every two office visits. Each prescription is for 1.2 to 1.4 items. Most of any GP's prescriptions are for a group of fewer than 30 different medications. Factors that influence prescribing include generic prescribing and knowledge of drug contents, provincial drug programs, physician and patient characteristics, type of practice, source of information about drugs, and rapidity of adoption of new drugs. The author offers suggestions for improving prescribing.