Physician Over-the-Counter Drug Prescribing Patterns: An Analysis of the National Ambulatory Medical Care Survey

OBJECTIVE: To describe the prevalence of physician over-the-counter (OTC) drug prescribing in relation to selected physician, patient, and drug characteristics. DATA SOURCE AND METHODS: Data from the 1990 National Ambulatory Medical Care Survey, a multistage probability clustered sample, were analyzed. Physician drug utilization was expressed in drug mentions defined as "the physician's entry of a pharmaceutical agent ordered or provided, by any route of administration, for prevention, diagnosis, or treatment." Sampling weights were used to obtain unbiased national estimates. Cross tabulations of the drug prescription status (OTC or prescription Rx) with independent variables were performed, overall and by therapeutic class. The overall OTC/Rx ratio (0.11) was used as the cutoff point for distinguishing high- from low-level OTC drug prescribing. RESULTS: In 1990, 9.7% of physician drug mentions were of OTC drugs. Women between 16 and 34 years, Asian/Pacific Islanders, white Hispanics, and African-Americans experienced high OTC drug mentions (OTC/Rx > or = 0.11). After stratification by drug therapeutic class, physicians in general practice, family practice, internal medicine, obstetrics/gynecology, and pediatrics highly mentioned OTC drugs. CONCLUSIONS: OTC drug prescribing by physicians is substantial, and primary care specialties, patient gender, age, and race should be considered by those interested in evaluating OTC drug utilization in the ambulatory care setting.