Physician and Practice Characteristics Associated with the Early Utilization of New Prescription Drugs

Background: Prescription of new drugs contributes to substantial increases in annual drug expenditures. A small proportion of physicians appear to be early users of new prescription drugs and little is known about their characteristics.

Objective: To estimate the initial utilization rate of new prescription drugs among physicians, and the physician and practice characteristics associated with early use.

Design: Cumulative prospective assessment over a 5 year period (1989-1994) of new drug utilization rates in a randomly selected cohort of Quebec physicians.

Participants: 1661 physicians and 669,867 elderly patients.

Outcome: Prescribing rate of 20 new drugs, in 6 therapeutic categories, to elderly patients in the first 6 months after inclusion in the Quebec formulary.

Results: The 20 new drugs were prescribed by 1.3-22.3% of physicians, and there was an 8 to 17-fold difference in new drug utilization rates among prescribers. Characteristics associated with higher rates of utilization differed for general practitioners and specialists. Male general practitioners, and physicians graduating from the most recently established medical school in the province, had higher rates of new drug utilization, whereas recent graduation was only associated with higher utilization rates among specialists. Practice volume was associated with higher rates of utilization among GPs. For both GPs and specialists, having a high proportion of elderly in one's practice and a rural or remote practice location was associated with lower utilization rates.

Conclusions: Physician sex, specialty, medical school, years since graduation, practice location, volume, and relative proportion of elderly in the physician's practice influence the utilization of new drugs.