Predictors of Broad-Spectrum Antibiotic Prescribing for Acute Respiratory Tract Infections in Adult Primary Care

CONTEXT: Broad-spectrum antibiotics are commonly prescribed, but little is known about the physicians who prescribe and the patients who take these agents. OBJECTIVE: To identify factors associated with prescribing of broad-spectrum antibiotics by physicians caring for patients with nonpneumonic acute respiratory tract infections (ARTIs). DESIGN, SETTING, AND PATIENTS: Cross-sectional study using data from the National Ambulatory Medical Care Survey between 1997 and 1999. Information was collected on a national sample of 1981 adults seen by physicians for the common cold and nonspecific upper respiratory tract infections (URTIs) (24%), acute sinusitis (24%), acute bronchitis (23%), otitis media (5%), pharyngitis, laryngitis, and tracheitis (11%), or more than 1 of the above diagnoses (13%). MAIN OUTCOME MEASURE: Prescription of broad-spectrum antibiotics, defined for this study as quinolones, amoxicillin/clavulanate, second- and third-generation cephalosporins, and azithromycin and clarithromycin. RESULTS: Antibiotics were prescribed to 63% of patients with an ARTI, ranging from 46% of patients with the common cold or nonspecific URTIs to 69% of patients with acute sinusitis. Broad-spectrum agents were chosen in 54% of patients prescribed an antibiotic, including 51% of patients with the common cold and nonspecific URTIs, 53% with acute sinusitis, 62% with acute bronchitis, and 65% with otitis media. Multivariable analysis identified several clinical and nonclinical factors associated with choice of a broad-spectrum agent. After adjusting for diagnosis and chronic comorbid illnesses, the strongest independent predictors of broad-spectrum antibiotic prescribing were physician specialty (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.6-3.5 for internal medicine physicians compared with general and family physicians) and geographic region (OR, 2.6; 95% CI, 1.4-4.8 for Northeast and OR, 2.4; 95% CI, 1.4-4.2 for South [both compared with West]). Other independent predictors of choosing a broad-spectrum agent included black race, lack of health insurance, and health maintenance organization membership, each of which was associated with lower rates of broad-spectrum prescribing. Patient age, sex, and urban vs rural location were not significantly associated with prescribing choice. CONCLUSIONS: Broad-spectrum antibiotics are commonly prescribed for the treatment of ARTIs, especially by internists and physicians in the Northeast and South. These high rates