Sociodemographic inequalities in urinary tract infection in two large California health systems
Abstract Background Urinary tract infection (UTI) accounts for a substantial portion of outpatient visits and antibiotic prescriptions in the United States (US). Few studies have considered sociodemographic factors including low socioeconomic status (SES)–which may increase residential crowding, inappropriate antibiotic prescribing, or co-morbidities–as UTI or multi-drug resistant (MDR) UTI risk factors. Methods We used 2015-2017 electronic health record data from two California healthcare systems to assess whether three sociodemographic factors–use of Medicaid, use of an interpreter, and census tract-level deprivation–were associated with overall UTI or MDR UTI. UTI resistant to ≥3 antibiotic classes were considered MDR. Results Analyses included 601,352 UTI cases, 1,303,455 controls, and 424,977 urinary E. coli isolates from Kaiser Permanente Southern California (KPSC) and Sutter Health in Northern California. MDR prevalence was 10.4% at KPSC and 12.8% at Sutter Health. All three sociodemographic factors (i.e., use of Medicaid, using an interpreter, and community deprivation) were associated increased risk of MDR UTI. For example, using an interpreter was associated with a 36% (RR = 1.36, 95% CI: 1.31, 1.40) and a 28% (RR = 1.28, 95% CI: 1.22, 1.34) increased risk of MDR UTI at KPSC and Sutter Health, respectively, adjusted for SES and other potential confounding variables. The three sociodemographic factors were only weakly associated with UTI overall. Conclusions We found low SES and use of an interpreter as novel risk factors for MDR UTI in the US.