Antibiotics for upper respiratory tract infections in ambulatory practice in the United States, 1997-1999: does physician specialty matter?

BACKGROUND The dangers of overuse of antibiotics for upper respiratory infections (URIs) has been widely recognized, but the rate of change in prescribing patterns in recent years is unknown. METHODS Data on the use of antibiotics for URIs was extracted from the 1997 to 1999 National Ambulatory Medical Care Survey (a national multistage probability sample survey of patients' office visits to office-based physicians). Adult patients (>/=18 years) with a primary diagnosis of URI (bronchitis, common colds, and other acute upper respiratory infections) were included. The decision to prescribe antibiotics was modeled as a function of patient, physician, and practice characteristics using logistic regression. RESULTS The rate of antibiotic prescription for URIs decreased from 52.1% in 1997 to 41.5% in 1999. In a multivariate logistic regression model, treatment by general internal medicine physicians [odds ratio (OR), 0.37; 95% confidence interval (CI), 0.18 to 0.76] was associated with lower prescription rates. Of patients visiting general internal medicine physicians for URIs, 36.2% received antibiotics compared with 42.9% of those seeing a general/family medicine physician. Patients treated by their primary care physicians had a higher risk of receiving antibiotics (OR, 1.70; 95% CI, 1.08 to 2.68). CONCLUSIONS Despite a downward trend in antibiotic prescribing over the years, overprescription of antibiotics for upper respiratory infections persists. General internal medicine physicians are less likely than general/family physicians to prescribe antibiotics, but this gap seems to be narrowing. Specific interventions must be designed to address these disparities.