Quality improvement initiative successfully reduced urine culture testing for asymptomatic bacteriuria and catheter-associated asymptomatic bacteriuria

By Pooja Toshniwal PahariaReviewed by Danielle Ellis, B.Sc.Mar 7 2023

In a recent study published in the American Journal of Infection Control, researchers reported on the execution of two electronic healthcare record (EHR) interventions for reducing urine culture (UC) ordering in asymptomatic bacteriuria (ASB) and catheter-associated ASB (CA-ASB) in a low-resource safety net system.

Background

ASB cases include 10⁵ colony-forming units (CFU) /mL of bacterial organisms, irrespective of pyuria, and no signs and symptoms of urinary tract infection (UTI). ASB is commonly observed among facility residents requiring care in the long term. The United States (US) preventive services task force, several Choosing Wisely lists, and the infectious disease society of America (IDSA) advise against ASB treatment due to concerns about side effects from antibiotic use, greater duration of stay, and antimicrobial resistance.

However, ASB treatment is frequently administered, with most UCs ordered inappropriately without particular indications. CA-ASB enhances the risk of bacteriuria. Ordering UCs unnecessarily could result in catheter-associated UTI (CAUTI) overdiagnoses and antimicrobial courses of greater duration.

Several institutional authorities have published interventions to decrease UC ordering. However, most studies used multipronged and resource-intensive methods. The execution of such interventions, although effective, could be challenging for locations with fewer resources, such as safety net settings.

About the study

In the present study, researchers presented interventions to reduce inappropriate UC ordering across 70 ambulatory clinics and 11 hospitals and in a safety net setting.

The study comprised two interventions- a compulsory prompt for UC indication and a best practice advisory (BPA) for UC ordering for individuals with urinary catheters. UC ordering was assessed comparatively in the pre and post-intervention periods, between June 2020 and October 2021 and December 2021 and August 2022, respectively.

The New York City (NYC) Health + Hospitals executed the initiative across 11 teaching hospitals providing acute care in a safe setting. The project lead was the New York City Health + Hospitals system high-value care council, and interdisciplinary inputs were provided by specialists related to infectious diseases, infection control, laboratory, patient safety, and nursing.

The interventions aimed to reduce unnecessary UC ordering and alert healthcare professionals of the elevated counts of ASB cases among individuals using foley catheters. Mandatory indications and BPA intervention were executed on 12 July 2021 and 12 October 2021, respectively. Clinicians had to select UC indications listed in the IDSA recommendations.

The initiative included stating the adverse effects of unnecessary UC ordering, including antimicrobial therapy. In addition, the project included normative nudging mentioning that the New York City Health + Hospitals council advocates UC ordering among individuals with symptomatic infections, except for pregnant women and those who underwent urological surgeries.

The BPA response is triggered if UCs for individuals using foley-type catheters were hospitalized for >2.0 days to meet CAUTI eligibility. Foley catheter records were obtained via the drains, airway, and lines, and the airway records were filled out by nurses. BPA responses were obtained from clinicians made aware of elevated rates of asymptomatic bacteriuria and bacterial colonization among individuals on foley catheters.

The prime study outcome comprised the count of UCs among every 1,000 individual-days for those using foley-type catheters following 2.0 days of hospitalization, compared to the preintervention (between 23 June 2020 and 11 October 2021) and the post-intervention period (between 7 December 2021 and 22 August 2022).

The second prime study outcome comprised the count of UCs among every 1,000 individual-days in the pre-intervention and post-intervention periods. The third study outcome comprised CAUTI rates pre-intervention and post-intervention. CAUTI was diagnosed using the national health care safety network definition 2020 to 2022. The BPA acceptance rate was determined.

Results

In the pre-intervention and post-intervention periods, the average patient age was 58 and 59 years, respectively. The BPA showed 4,822 triggers, and 552 UC orders were canceled, with an 11.0% BPA acceptance rate. For patients with urinary catheters 2.0 days post-hospitalization, UC ordering reduced from 2.40 for every 1,000 individual-days in the pre-intervention period to 1.90 for every 1,000 individual days post-intervention (22.0% decrease).

UC ordering among inpatients reduced from 33.0 (for every 1,000 individual days) in the pre-intervention period to 26.0 in the post-intervention period (21.0 % decrease). On the contrary, UC ordering for patients was largely unaltered. Highly variable temporal patterns were observed among clinics and hospitals.

Low BPA acceptance rates were associated with family medicine and internal medicine clinicians. CAUTI rates pre-intervention were 2.0, reducing to 1.6 post-intervention. The team decreased UC ordering by implementing two interventions. Across 11 hospitals, the modeling estimates were scaled in an extensive safety net system of the US.

Conclusion

Overall, the study findings showed that the quality improvement project successfully reduced UC ordering in a large, safety-net setting. However, further research is required to assess variations among clinics, hospitals, and clinician specialties. The initiative’s success could be generalized to other hospital-acquired infections, including Clostridioides difficile infections, or for another low-value testing, such as fecal culture for hospital-acquired diarrhea.