Antimicrobial stewardship to reduce overtreatment of asymptomatic bacteriuria in critical access hospitals: measuring a quality improvement intervention.

Background: Asymptomatic bacteriuria (ASB) treatment is a common form of antibiotic overuse and diagnostic error. Antibiotic stewardship using the inappropriate diagnosis of urinary tract infection (ID-UTI) measure has reduced ASB treatment in diverse hospitals. However, critical access hospitals (CAHs) have differing resources that could impede stewardship. We aimed to determine if stewardship including the ID-UTI measure could reduce ASB treatment in CAHs.

Methods: From October 2022 to July 2023, ten CAHs participated in an Intensive Quality Improvement Cohort (IQIC) program including 3 interventions to reduce ASB treatment: 1) learning labs (ie, didactics with shared learning), 2) mentoring, and 3) data-driven performance reports including hospital peer comparison based on the ID-UTI measure. To assess effectiveness of the IQIC program, change in the ID-UTI measure (ie, percentage of patients treated for a UTI who had ASB) was compared to two non-equivalent control outcomes (antibiotic duration and unjustified fluoroquinolone use).

Results: Ten CAHs abstracted a total of 608 positive urine culture cases. Over the cohort period, the percentage of patients treated for a UTI who had ASB declined (aOR per month = 0.935, 95% CI: 0.873, 1.001, P = 0.055) from 28.4% (range across hospitals, 0%-63%) in the first to 18.6% (range, 0%-33%) in the final month. In contrast, antibiotic duration and unjustified fluoroquinolone use were unchanged (P = 0.768 and 0.567, respectively).

Conclusions: The IQIC intervention, including learning labs, mentoring, and performance reports using the ID-UTI measure, was associated with a non-significant decrease in treatment of ASB, while control outcomes (duration and unjustified fluoroquinolone use) did not change.