Antibiotic Duration and UTI Outcomes in Recurrent UTI Patients.

IMPORTANCE: Little evidence is available to inform management of acute urinary tract infections (UTIs) in women with recurrent urinary tract infection (rUTI).

OBJECTIVE: This study aimed to compare the proportion of acute UTIs with persistence/relapse or recurrence based on duration of treatment antibiotics (acute UTI guideline-consistent versus extended).

STUDY DESIGN: A retrospective noninferiority study of women with rUTI was performed at an academic tertiary referral center from January 2016 to December 2020. Exposure was UTI treatment with acute UTI guideline-consistent versus extended antibiotics. Outcomes were persistent/relapsed UTI (subsequent culture with the same pathogen requiring additional antibiotics within 4 weeks), recurrent UTI (culture with different pathogen), or resolution. Sample size was calculated under the null hypothesis that the proportion of acute UTIs with persistence/relapse or recurrence after acute UTI guideline-consistent antibiotics would be within a 10% noninferiority margin of extended duration (α = 0.05, β = 0.20, 2-sided tests, P < 0.05 significant).

RESULTS: We included 219 patients with 553 acute UTIs. The mean ± SD number of UTIs per patient was 2.53 ± 1.88, the mean ± SD age was 68.60 ± 16.29 years, and the mean ± SD body mass index was 29.73 ± 7 (calculated as weight in kilograms divided by height in meters squared). There were no differences in prior surgical procedures postvoid residual volume, pelvic floor disorders, or preventive treatments between groups. Two-hundred sixty UTIs (260 of 553 [47%]) were treated with acute UTI guideline-consistent antibiotics. Overall, 86 of 553 UTIs (15.6%) persisted/relapsed, and 29 of 553 (5.2%) recurred. The difference in the proportions of UTIs with persistence/relapse or recurrence excluded the noninferiority margin (4.4%; 95% confidence interval, -0.04 to 6.80%). In total, 115 of 553 UTIs (20.8%) had persistence/relapse or recurrence.

CONCLUSION: In this cohort of patients with rUTI experiencing acute UTIs, acute UTI guideline-consistent duration of antibiotics was noninferior.