Nearly half of US women with an uncomplicated urinary tract infection (UTI) receive an inappropriate antibiotic prescription, and nearly three-quarters receive a prescription that is longer than necessary, according to a study last week in Infection Control & Hospital Epidemiology.
The study, led by researchers from Washington University School of Medicine in St. Louis, also found that women in rural areas are more likely to receive an inappropriately long antibiotic prescription.
Uncomplicated UTIs account for roughly 10.5 million medical office visits annually and an additional 2 to 3 million emergency department visits. But antibiotic prescriptions for UTIs are frequently not in accordance with guidelines. The authors of the study say the purpose of the study was to get a better understanding of the settings characterized by higher inappropriate prescribing.
"Given that uncomplicated UTIs are one of the most common indications for antibiotic prescribing in otherwise healthy populations, we wanted to identify targets for interventions designed to improve guideline adherence," explained lead study author Anne Butler, PhD, a professor of medicine and surgery at Washington University School of Medicine.
Longer durations in rural settings
The findings are based on an analysis of insurance claims data on 670,450 women ages 18 to 44 who were diagnosed with an uncomplicated UTI and received an antibiotic prescription from April 2011 through June 2015. Butler and her colleagues classified antibiotic prescriptions as either appropriate or inappropriate based on Infectious Diseases Society of America (IDSA) recommendations for first-line agents for uncomplicated UTIs and on the IDSA-recommended durations.
For treatment of uncomplicated UTIs, IDSA recommends nitrofurantoin for 5 days, trimethoprim-sulfamethoxazole for 3 days, or fosfomycin for 1 day. The researchers classified fluoroquinolones (3 days), beta-lactams (3 to 7 days), and trimethoprim monotherapy (3 days) as inappropriate.
To address any rural-urban differences in inappropriate prescribing, as identified in previous studies on respiratory and pediatric infections, the authors categorized women by residence in a metropolitan statistical area, then compared rural and urban antibiotic usage patterns. Of the women included in the study, 86.2% were from urban areas and 13.8% were from rural areas. The study also broke down prescribing by geographic region and provider type.
Overall, 46.7% of the women received an inappropriate antibiotic, most commonly fluoroquinolones (41.6%), while 76.1% received an antibiotic for an inappropriate duration, with nearly all of those prescriptions (98.8%) written for a duration that was longer than necessary. The proportion of women receiving inappropriate antibiotics and inappropriate antibiotic durations by quarter declined over the course of the study—from 48.5% to 43.7% and 78.3% to 73.4%, respectively.
Overall, a similar proportion of rural and urban women received an inappropriate antibiotic (45.9% versus 46.9%), and multivariable analysis of the rural-urban breakdown showed little difference in the risk of rural women receiving an inappropriate agent (adjusted risk ratio [RR], 0.98; 95% confidence interval [CI], 0.98 to 0.99) compared with urban women. Women in the South and the West, regardless of whether they lived in an urban or rural area, were more likely to receive inappropriate agents.
But rural women were prescribed inappropriate antibiotic durations more frequently than urban women (83.9% versus 74.9%), and in the multivariable analysis, were 10% more likely to receive an antibiotic for an inappropriate duration (adjusted RR, 1.10; 95% CI, 1.10 to 1.10).
"These differences in inappropriate duration were consistent across antibiotic agents, geographic regions, and provider specialties," Butler said.
Rural-urban differences in appropriate antibiotic durations remained generally constant over the course of the study within subgroups of antibiotic agent, geographic region, and provider specialty.
Distance to healthcare may be factor
The high rate of inappropriate UTI prescribing observed in the study is not surprising. Previous research has shown that clinicians prescribe fluoroquinolones in more than 40% of uncomplicated UTIs, likely because of concerns about rising resistance to narrow-spectrum antibiotics in Escherichia coli—the predominant bacterial cause of UTIs. But Butler and her colleagues say they're not aware of regional uropathogen resistance data in the United States that compare with their findings.
As for the increased risk of rural women getting an inappropriately long antibiotic prescription, they suggest that distance to healthcare may be a factor. Rural residents tend to live farther away from healthcare providers than urban residents, and providers might be prescribing an antibiotic for a longer duration to avoid a treatment-related failure that would require the patient to travel. In addition, they note that late-career physicians, who are more prevalent in rural locations, are more likely to write longer antibiotic prescriptions.
Butler said the findings highlight the need to identify reasons for higher inappropriate prescribing for UTIs in both rural and urban settings and to develop antibiotic stewardship interventions to improve prescribing for UTIs and other outpatient conditions.
"Although we observed differences between rural and urban prescribing, inappropriate prescribing was rampant in both rural and urban settings," Butler said. "Development of future strategies to improve antibiotic prescribing should consider that inappropriate prescribing is common in all settings, but higher in rural settings."