How to Reduce Unnecessary Urine Cultures Among Hospitalized Patients

Too often, the isolation of bacteria in the absence of symptoms or signs of a urinary tract infection (UTI) is overdiagnosed and overtreated in the United States, and low-resource approaches could help reduce the overdiagnosis and overtreatment of asymptomatic bacteriuria, according to a recent study conducted at the NYC Health + Hospitals (NYC H+H).

Infection Control Today^® (ICT^®) spoke with Mona Krouss, MD, Assistant Vice President of Value and Patient Safety, NYC Health + Hospitals (NYC H+H), and the lead author of the published study. Published in the American Journal of Infection Control, the study is titled, “Choosing wisely initiative for reducing urine cultures for asymptomatic bacteriuria and catheter-associated asymptomatic bacteriuria in an 11-hospital safety net system.”

ICT: Would you please tell our audience the key findings and why they are important?

Mona Krouss, MD: We created 2 electronic health record interventions. One was a mandatory indication for urine cultures, which has been done before and in previous studies. But then, specifically for patients who are ordered urine cultures on patients with urinary catheters, we created an alert that would trigger stating that most patients with Foley catheters are colonized with bacteria. But it's not a true infection. We implemented that alert at 11 acute care hospitals in New York City with only the electronic health record intervention. No other [quality improvement] initiatives like education, audit, feedback, or additional stewardship were used.

We had great results. These interventions decreased overall urine cultures by 20%. And then those urine cultures, specifically with patients with Foley catheters by 22%, our CAUTI [Catheter-associated urinary tract infections] rates didn't change, but our quality improvement [QI] study wasn't powered to detect a difference. This is important because it's a relatively low-effort intervention and very scalable across the 11 hospitals. So we implemented it at one time, and all our hospitals have the same electronic health record. And you know, traditional QI projects utilize education, stewardship, and many high-intensity resources. And, as a safety net system, we don't have the resources to do this across all the hospitals. As a safety net hospital, we also don't have many infection preventionists in our departments to chase after every urine culture, so it's important because of the low effort it took to get these great results.

We have infection preventionists at all our hospitals, but they need more robust departments.

ICT: What is the practical application for the critical findings for infection preventionists?

MK: This is a tool that infection preventionists can use. Some hospitals have the ability for urine cultures to be, especially those in patients with Foley catheters that, you know, some hospitals have them approved by infection preventionist before they can proceed with the order. Again, hospitals like ours need more resources to do this. But even if you do that in your hospital, this would be a way to catch the user in the moment. And then, if they chose to proceed with the urine culture, you could have that second review by an infection preventionist. But again, if you need more resources to do this, this is a way to do stewardship through the electronic health record.

ICT: Were there any results that surprised you?

MK: The differences in the hospitals were interesting. Out of the 11 hospitals, all had reductions in urine cultures, ranging from 10% to 30%. We wondered if there were any trends in this, like did the larger hospitals have a smaller decrease or did our trauma hospitals have a difference in the reduction, but there weren't any themes we could identify. This might be due to the infection preventionists making other education or stewardship efforts that we should have been aware of. However, the variability was interesting.

ICT: Do you have any future research coming out of or going along with this study?

MK: In this study, we didn't look at antibiotic rates; we assumed that if people ordered fewer urine cultures, there would be less antibiotic use. But our next step is to see how it affected antibiotic use and look over a more extended period to see if we see differences in our quality rates. Because of the way we looked at the intervention and the period, it probably needed to be longer to detect those rates. But we do want to see if it in the future affects it over time.

ICT: How big are these hospitals? How big is this hospital system that you did this test in the study?

Eleven hospitals range from more minor to very large hospitals. The most famous hospital in our system is Bellevue Hospital. They're in all different boroughs of New York City, and 6 of our 11 are hospitals or trauma centers. The others are small community centers. It's a big range of size and complexity, and the patients they see because they are in different boroughs.

ICT: This is great because now your study has a wide variety of hospitals to take that information and compare them. It gives strong validity to your research. So how long was the study done?

MK: Our intervention was implemented in December 2021 and carried out through August 2022. It's still going on. The good thing about an electronic health intervention is that once you implement it, it is very easy to sustain. Because there is no repeat education or having to go around and tell people again; that's the beauty of it. It's a very low effort comparing it to other QI.

ICT: Have you thought about adding that educational aspect to the study?

MK: With anything, education is always important. And we must know why we're asking people not to order urine cultures on everyone. It is important to know the why behind it; we try to incorporate education into any electronic health record intervention. It tells you that, for example, IDSA [Infectious Diseases Society of America] recommends only testing for symptomatic patients. It means you know that when you have a urinary catheter, you have a high colonization rate, but the on the ground education is important too. For that to happen across 11 hospitals, we must have champions and people who would continue these educational efforts. So that's something that we're thinking about for the future.

ICT: Is there anything else you would like to tell our readers?

MK: I hope they can use this model and tool in their hospitals, especially for hospitals with scarce resources like ours.

The study was published at the beginning of March 2023.

This interview has been edited for length and clarity.