2834. Comparative Effectiveness of Oral Antibiotics to Treat Urinary Tract Infections in Male and Female Outpatients

Abstract Background Professional and regulatory agency guidelines recommend that fluoroquinolones not be used as first-line therapy to treat uncomplicated UTI. Increasingly, β-lactams are being used to treat UTI despite limited evidence supporting their effectiveness. The study aim was to compare the efficacy of β-lactams and other commonly prescribed antibiotics for UTI to fluoroquinolones. Methods A multi-centered retrospective cohort study of outpatient visits with a UTI diagnosis between 2019-2021 was developed. Inclusion criteria: In-person visit in the Emergency Department or Primary/Urgent Care with ICD-10 documented UTI diagnosis and oral antibiotic prescription filled within 0-2 d. Exclusion criteria: Prior UTI < 30d, co-diagnosis where antibiotics were indicated, hospital discharge < 7d, scheduled urological procedure < 7d, pregnancy. Outcome: UTI related admission or outpatient return visit within 3-30d. Demographic, co-morbidity, vitals, laboratory, and prescription data were extracted. Propensity scores were used to balance treatments and GEE models were used to estimate outcomes. Results There were 73,334 visits in 130 VA medical centers. Mean (S.D.) cohort age was 66.0 (15.8) y, 22.9% were female. Antibiotics prescribed N (%): β-lactams (cephalosporins, aminopenicillins) 27,385 (37.3%), nitrofurantoin 15,509 (21.1%), trimethoprim / sulfamethoxazole (TMP/SMX) 15,453 (21.1%), and fluoroquinolones 14,997 (20.4%). The overall 30-day clinical failure rate was 10,525 (14.4%). Comparative Effectiveness of Oral Antibiotics for Outpatient UTIs Conclusion Commonly prescribed antibiotics for outpatient UTI were associated with a modest increase in 30-day clinical failure relative to fluoroquinolones. Effectiveness differences were most pronounced in male patients. Clinicians should carefully differentiate between complicated and uncomplicated UTI in males and consider preferentially prescribing fluoroquinolones. Disclosures Karl Madaras-Kelly, PharmD, MPH, BioMerioux: Grant/Research Support