Risk factors for recurrent urinary tract infections among women in a large integrated health care organization in the United States.

BACKGROUND: Urinary tract infections (UTIs) occur commonly and often recur. However, recent data on the epidemiology of recurrent UTI (rUTI) are scarce. METHODS: Between 01/01/2016-31/12/2020, index uncomplicated UTIs (uUTI) from office, emergency department (ED), hospital, and virtual care settings were identified from electronic health records of women at Kaiser Permanente Southern California. We defined rUTI as ≥3 UTI within 365 days or ≥2 UTI within 180 days. We determined the proportion of women with cystitis index uUTI who had rUTI and examined factors associated with rUTIs using modified multivariable Poisson regression. RESULTS: Among 374,171 women with cystitis index uUTI, 54,318 (14.5%) had rUTI. A higher proportion of women with rUTI compared to those without rUTI were age 18-27 or ≥78 years at index uUTI (19.7% vs 18.7% and 9.0% vs 6.0%, respectively), were immunocompromised, or had a positive urine culture at index uUTI. In multivariable analyses, characteristics associated with rUTI included younger or older age (48-57 vs 18-27 years aRR=0.83 [95% CI: 0.80-0.85]; ≥78 vs 18-27 years aRR=1.07 [95%CI=1.03-1.11]), Charlson Comorbidity Index (≥3 vs 0, aRR=1.12 [95%CI:1.08-1.17]), and diabetes mellitus (aRR=1.07 [95%CI:1.04-1.10]). More frequent prior year outpatient and ED encounters, oral antibiotic prescriptions, oral contraceptive prescriptions, positive culture at index uUTI, and antibiotic resistant organisms were also associated with increased risk of rUTI. CONCLUSIONS: The high risk of rUTI among women with cystitis is concerning, especially given previous reports of increasing UTI incidence. Current assessment of the epidemiology of rUTI may guide the development of preventive interventions against UTI.

Antibiotic resistance of urinary tract infection recurrences in a large U.S. integrated health care system.

BACKGROUND: Data on antibiotic resistance of uropathogens for UTI recurrences are lacking. METHODS: In a retrospective cohort of adults at Kaiser Permanente Southern California with culture-confirmed index uncomplicated UTI (uUTI) between 01/2016 and 12/2020, we examined the number and characteristics of subsequent culture-confirmed UTIs through 2021. RESULTS: We identified 148,994 individuals with a culture-confirmed index uUTI (88% female, 44% Hispanic, mean age 51 years [s.d. 19]), of whom 19% developed a subsequent culture-confirmed UTI after a median 300 days (IQR: 126-627). The proportion of UTI due to E. coli was highest for index uUTI (79%) and decreased to 73% for sixth UTI (UTI 6) (p-for trend <0.001), while the proportion due to Klebsiella spp increased from index UTI (7%) to UTI 6 (11%) (p-for-trend <0.001). Non-susceptibility to ≥1 and ≥3 antibiotic classes was observed in 57% and 13% of index uUTIs, respectively, and was higher for subsequent UTIs (65% and 20%, respectively, for UTI 6). Most commonly observed antibiotic non-susceptibility patterns included penicillins alone (12%), and penicillins, trimethoprim-sulfamethoxazole plus ≥1 additional antibiotic class (9%). CONCLUSIONS: Antibiotic non-susceptibility is common in UTIs and increases with subsequent UTIs. Continuous monitoring of UTI recurrences and susceptibility patterns are needed to guide treatment decisions.