Outpatient Prescribing Patterns for Uncomplicated Cystitis in Premenopausal Women With and Without an Allergy to Guideline-Recommended Antimicrobials: A Retrospective Analysis

Abstract

Objective: To determine if premenopausal women 18 to 50 years of age with uncomplicated cystitis who have an allergy to a guideline-recommended antimicrobial agent are less likely to receive guideline-preferred treatment compared to women without an allergy. Methods: An electronic medical record report was used to identify females between the ages of 18-50 with a diagnostic code for acute uncomplicated cystitis at outpatient visits between December 1, 2017, through December 31, 2021. Patients with complicated urinary tract infections or pyelonephritis were excluded. After identifying the eligible encounters, a retrospective chart review was used to collect demographic information, known antimicrobial allergies, urinalysis and culture results, and prescribed antimicrobials. The primary outcome was a receipt of a guideline-preferred antimicrobial. Secondary outcomes included fluoroquinolone utilization and resistance patterns, as well as subgroup analyses of patients with specific allergies to guideline-preferred agents. Results: A total of 496 patient encounters were screened for inclusion, with 165 meeting the inclusion criteria. Of those, 38 encounters were identified as having a documented antimicrobial allergy (23%) to a guideline-recommended agent. Demographic and clinical characteristics were similar between patients with and without antimicrobial allergies, except for race. Beta-lactam allergies were the most frequently documented antimicrobial allergy. All 165 patients received a guideline-recommended therapy, and 92 received a guideline-preferred agent (56%). Patient encounters without an antimicrobial allergy were numerically but not significantly more likely to receive guideline-preferred therapy (75 of 127 patients, 59%) compared to those with an allergy (17 of 38 patients, 45%; p=0.12). Patient encounters with an antimicrobial allergy were significantly more likely to receive a fluoroquinolone (FQ) prescription (n=6/38, 16%) compared to those without allergies (n=2/127, 1.6%; p=0.002). A subgroup analysis of patients with an allergy to a preferred agent was statistically less likely to receive a guideline-preferred treatment and more likely to receive an alternative agent. No statistical differences in other secondary outcomes were observed. Conclusion: Premenopausal women with a documented antimicrobial allergy were statistically more likely to receive fluoroquinolone. Prescribers may be less likely to select a guideline-preferred treatment where antimicrobial allergies exist. Providers should be educated on evidence-based treatment within this population.