Outpatient Antibiotic Prescribing for Urinary Tract Infections in Women in the United States: 2000-2010

Background: Urinary tract infections (UTI) are a leading cause of infection in the U.S. Resistance has emerged to several of the antibiotics commonly used to treat UTIs, such as β-lactams, trimethoprim-sulfamethoxazole, and fluoroquinolones; however, it is unknown whether recent prescribing patterns of these antibiotics have changed in response to emerging resistance. We describe national trends of outpatient antibiotic prescribing for UTIs in women from 2000 to 2010. 

Methods:   This was a cross-sectional study using nationally representative data from the Medical Expenditure Panel Survey (MEPS) from 2000 to 2010. Eligible cases were limited to women > 18 years of age, who had an ICD-9 CM diagnosis code for either acute cystitis (595) or UTI site unspecified (599). The proportion of visits at which physicians prescribed β-lactams, trimethoprim-sulfamethoxazole, quinolones, or nitrofurantoin were evaluated. Annual prescription rates were reported per 1,000 persons and population estimates were obtained from the U.S. Census Bureau. Data weights were used to derive national estimates. 

Results: This cohort represents over 75 million ambulatory care visits for UTIs from 2000 to 2010. The yearly rate of outpatient antibiotic prescriptions for UTIs increased from 40 per 1,000 women in 2000 to 54 per 1,000 women in 2010. The proportion of UTI visits where an antibiotic was prescribed increased from 58% in 2000 to 89% in 2010. The most frequently prescribed antibiotics were quinolones (28%), nitrofurantoin (24%), and trimethoprim-sulfamethoxazole (18%). Nitrofurantoin use increased from 2000 to 2010 (21% v 26%; RR 1.23, 95%CI 1.23-1.25); whereas, β-lactam use (18% v 11%; 0.61, 0.60-0.62) and trimethoprim-sulfamethoxazole use (19% v 15%; 0.78, 0.77-0.79) decreased. Quinolone use remained stable (28% v 28%; 0.99, 0.99-1.00). 

Conclusion: Outpatient antibiotic prescribing for UTIs among U.S. women has increased over the last decade. Nitrofurantoin prescribing has increased, β-lactam and trimethoprim-sulfamethoxazole prescribing have decreased, and quinolone prescribing has remained stable. Quinolones were the most frequently prescribed antibiotics over the entire study period, even though they are not highly recommended as first line therapy. This suggests opportunities exist to improve outpatient antibiotic prescribing for UTIs.