Incidence of urosepsis or pyelonephritis after uncomplicated urinary tract infection in older women

Introduction and hypothesis Our primary aim was to describe the incidence of the diagnosis of urosepsis or pyelonephritis during the 60 days following initial evaluation of an uncomplicated urinary tract infection (UTI) among female Medicare beneficiaries ≥ 65 years of age. Study design This was a retrospective cohort study of women ≥ 65 years of age undergoing evaluation for an incident, uncomplicated urinary tract infection (UTI) between the years 2011–2018 included in the Medicare 5% Limited Data Set (LDS). We grouped women into age categories of 65–74 years, 75–84 years, or > 84 years old. We excluded women with possible complicated UTI, those hospitalized within 60 days prior to index UTI evaluation, and those residing in a nursing home and place of service consistent with an inpatient setting/facility. The association between age and risk of each outcome was estimated with Cox proportional hazards models, controlling for relevant comorbidities. Results Between 2011–2018, 169,958 women met our inclusion/exclusion criteria and were evaluated for uncomplicated UTI. In total, 2935 (1.7%) had a subsequent diagnosis of either urosepsis ( n = 2848, 1.6%) or pyelonephritis ( n = 145, 0.08%). In adjusted analysis, the hazard of urosepsis was significantly higher for women > 84 years (aHR 1.49, 95% CI 1.38, 1.65; p < 0.01) and those aged 75–84 (aHR 1.24, 95% CI 1.13, 1.37; p < 0.01) compared to those aged 65–74 years. In contrast, age group was not significantly associated with the hazard for pyelonephritis. Conclusions Urosepsis and pyelonephritis are very uncommon after evaluation of incident uncomplicated UTI in female medical beneficiaries ≥ 65 years of age.