Patient Characteristics and Clinical Outcomes of Acute Pyelonephritis Treated in Mayo Clinic's Hospital-at-Home Program.

Background: Outcomes of patients with acute pyelonephritis (AP) treated in a hospital-at-home setting have not been comprehensively evaluated in the United States. Methods: We performed a multicenter, retrospective cohort study of adults diagnosed with and managed for AP in Mayo Clinic's Advanced Care at Home (ACH) program between July 2020 and January 2025. Collected data included demographics, Charlson Comorbidity Index (CCI), genitourinary comorbidities, severity of illness (SOI), and risk of mortality (ROM) scores, as well as pyelonephritis-related complications. Outcomes included length of stay (LOS), escalation of care, and 30-day postdischarge emergency department (ED) visits, readmissions, and mortality. Results: A total of 165 patients met inclusion criteria. Median age was 67 years; SOI scores were moderate in 33.3%, major in 52.1%, and extreme in 8.5%. ROM scores were moderate in 30.3%, major in 38.2%, and extreme in 6.7%. Median CCI score was 5, and all patients had preexisting genitourinary conditions. On admission, 30.9% met sepsis criteria, acute kidney injury was present in 47.3%, and bacteremia developed in 33.3%. Median LOS in the ACH program was 3.1 days. Only 4.8% required escalation to a brick-and-mortar hospital. Readmission occurred in 17.0%, and 4.8% had ED visits. No in-program deaths occurred. Conclusions: This multicenter retrospective study shows that AP, including cases with high illness severity and complex comorbidities, can be managed safely and effectively in a hospital-at-home setting with careful patient selection and robust infrastructure to support timely escalation when needed.