Descriptive Epidemiology and Outcomes of Hospitalizations With Complicated Urinary Tract Infections in the United States, 2018.

Background: Hospitalizations with complicated urinary tract infection (cUTI) in the United States have increased. Though most often studied as a subset of cUTI, catheter-associated UTI (CAUTI) afflicts a different population of patients and carries outcomes distinct from non-CA cUTI (nCAcUTI). We examined the epidemiology and outcomes of hospitalizations in these groups.

Methods: We conducted a cross-sectional multicenter study within the 2018 National Inpatient Sample (NIS) database, a 20% stratified sample of discharges from US community hospitals, to explore characteristics and outcomes of patients discharged with a UTI diagnosis. We divided cUTI into mutually exclusive categories of nCAcUTI and CAUTI. We applied survey methods to develop national estimates.

Results: Among 2837385 discharges with a UTI code, 500400 (17.6%, 19.8% principal diagnosis [PD]) were nCAcUTI and 126120 (4.4%, 63.8% PD) were CAUTI. Though similar in age (CAUTI, 70.1 years; and nCAcUTI, 69.7 years), patients with nCAcUTI had lower comorbidity (mean Charlson, 4.3) than those with CAUTI (mean Charlson, 4.6). Median (interquartile range [IQR]) length of stay (LOS) was 5 (3-8) days in nCAcUTI and 5 (3-9) days in CAUTI. Overall median (IQR) hospital costs were similar in nCAcUTI ($9713 [$5923-$17423]) and CAUTI ($9711 [$5969-$17420]). Though low in both groups, hospital mortality was lower in nCAcUTI (2.8%) than in CAUTI (3.4%). Routine discharges home were higher in nCAcUTI (41.5%) than CAUTI (22.1%).

Conclusions: There are >626000 hospital admissions with a cUTI, comprising ~1.8% of all annual admissions in the United States; 4/5 are nCAcUTI. Because CAUTI is frequently the reason for admission, preventive efforts are needed beyond the acute care setting.