Industry-funded study identifies risk factors for UTI treatment failure

Prior infections requiring antibiotic prescription and residency in the Southern U.S. increase the risk of treatment failure in female outpatients with uncomplicated urinary tract infections (UTIs), an industry-funded observational study found.

Using electronic health record (EHR) data from January 2017 to September 2022, researchers identified female patients at least 12 years of age who had at least one UTI diagnosis in an outpatient ambulatory setting or ED, at least one empiric oral antibiotic prescription, and no evidence of a complicated UTI. Treatment failure was defined as having a new/repeat oral antibiotic prescription, IV antibiotic administration, or acute UTI diagnosis at or within 28 days of the initial oral antibiotic prescription. The average age of patients with and without treatment failure was 48.9 years and 46.5 years, respectively; the majority were White and from the Midwest. Findings of the study, which was conducted by GSK, were published by the Journal of Internal Medicine on Oct. 2.

A total of 376,004 patients in the dataset had an uncomplicated UTI, and of these, 62,873 (16.7%) experienced treatment failure. Incidence was highest in patients who had a history of antibiotic treatment failure (33.9%) or who were prescribed fosfomycin (30.1%), though this prescription was uncommon (<5% of patients). Average time to treatment failure was 7.5 days. Having three or more antibiotic prescriptions (adjusted risk ratio [aRR], 1.60; 95% CI, 1.56 to 1.64) and a fosfomycin prescription (aRR, 1.60; 95% CI, 1.38 to 1.86) were significant risk factors for treatment failure, as were being diagnosed with an uncomplicated UTI in the ED (aRR, 1.49; 95% CI, 1.46 to 1.52), being a resident of the Southern U.S. versus the Midwest (aRR, 1.37; 95% CI, 1.35 to 1.40), and being 75 years of age or older (aRR, 1.35; 95% CI, 1.29 to 1.41). Recurrent UTI (aRR, 1.12; 95% CI, 1.10 to 1.14), and obesity (aRR, 1.06; 95% CI, 1.04 to 1.08) were other significant risk factors.

Among other limitations, the study did not require urinalysis- or culture-proven UTI, the authors noted. They wrote that the findings “highlight the sub-populations at elevated risk for [treatment failure], among whom urinalysis may enhance treatment decision-making and mitigate the risk of antibiotic overprescribing in clinical practice.”

Overall, knowledge of these risk factors can “inform shared-decision making and supplement existing guidance on appropriate oral antibiotic treatment selection for [uncomplicated] UTI in relation to known local antimicrobial susceptibility patterns, urine analysis, and the potential need for urine culture and sensitivity testing,” they concluded.