The Impact of Educational Interventions on Management of Asymptomatic Bacteriuria in the Emergency Department

Patients with asymptomatic bacteriuria (ASB) often do not meet the requirements for treatment but will still receive unnecessary antibiotics. Unnecessary antibiotics provide no benefit, while increasing the risk of antimicrobial resistance, Clostridium difficile (C. difficile) infection, adverse effects of the antibiotics prescribed, and increased hospital length of stay. The purpose of this study is to assess the impact of antimicrobial stewardship education on the rate of antibiotic prescribing for ASB in the emergency department.

Adult patients with a positive urine culture who presented to the Duke University Hospital emergency department were included. Patients were excluded if the urine culture grew mixed flora or yeast. Data was collected before and after antimicrobial stewardship education interventions. The primary outcome was the incidence of patients receiving appropriate treatment for ASB which consisted of the absence of antibiotic prescriptions. Secondary outcomes included median duration of antibiotic therapy, rate of adverse reactions within 7 days of treatment, and rate of C. difficile infections within 30 days.

The pre-intervention period included 90 encounters, and the post-intervention period included 115 encounters. The average patient age was 65.5 years. Most patients included were white (55.6%) and female (61.5%). Appropriate treatment for ASB occurred in 10/40 (25%; 95% CI: 11.6%, 38.4%) encounters during the pre-intervention period and 15/51 (29.4%; 95% CI: 16.9%, 41.9%) encounters during the post-intervention period. The median treatment duration for those receiving inappropriate ASB treatment was 6.5 days in the pre-intervention period and 8 days post-intervention. Adverse drug reactions occurred in no encounters in the pre-intervention period and in 12.2% of encounters during the post-intervention period. In the post-intervention period, the most common adverse effect was gastrointestinal effects. C. difficile infections occurred in no encounters in the pre-intervention period and in 3.5% of encounters in the post-intervention period.

There is insufficient evidence to show a difference in the rate of appropriate ASB treatment before and after antimicrobial stewardship education interventions. Future studies can assess individualized or institution-specific interventions to improve ED antibiotic use.