Assessment of Outpatient and Inpatient Antibiotic Treatment Patterns and Health Care Costs of Patients with Complicated Urinary Tract Infections

Abstract Purpose The goal of this study was to examine treatment patterns, utilization, and costs for complicated urinary tract infections (UTIs) requiring inpatient/emergency department (ED) and outpatient care. Methods This observational study evaluated inpatient/ED-treated and outpatient-treated patients (aged ≥18 years) with complicated UTIs from 2 large US administrative claims databases (HealthCore Integrated Research Environment and Premier Perspective Database). Patient identification depended on treatment setting: outpatients had 2 UTI diagnosis–related office visits and 2 claims for different antibiotics within 30 days, and inpatients had a UTI-related hospitalization/ED visit after 1 UTI diagnosis–related office visit plus 2 claims for different antibiotics within 30 days. The index date for outpatients was the date of the first office visit; for inpatients, it was the date of admission/ED visit. Both cohorts had continuous insurance eligibility. Outcomes were assessed by using univariate and multivariate statistics. Findings The study sample included 1118 inpatient/ED patients (76.6% female subjects; mean age, 62.4 years) and 41,605 outpatients (85.8% female subjects; mean age, 52.3 years). Mean (SD) pharmacy costs were $2971 ($7650) for inpatient/ED patients and $1882 ($3120) for outpatients during the full treatment period. Index hospitalization/ED averaged $38,422 ($51,161). Mean all-cause 90-day follow-up costs for the inpatient/ED cohort were $34,100 ($71,621) and $11,345 ($34,313) for the outpatient cohort. Implications Relative to outpatient-treated patients, inpatient/ED-treated patients were older, sicker, had higher costs across treatment periods, and had reduced antibiotic use at a lower rate during the 90-day follow-up. Strategies to avoid preventable inpatient/ED visits may help reduce costs in the management of outpatients with complicated UTIs.