Urine test ordering—good and going for better

Charna Albert

December 2022—Reflex urine culture algorithms have become common and have been shown to reduce urine culture utilization, but efforts to sharpen clinical decision support continue.

“You want to make it as easy as possible to do the right thing,” says Jessica Howard-Anderson, MD, MSc, assistant professor of medicine, Emory University School of Medicine, and associate hospital epidemiologist, Emory University Hospital Midtown. She advises making the reflex culture the default pathway. And when it comes to educational support on appropriate urine test ordering, “you don’t want that to be something that they [physicians] always have to click through or take a lot of time to read to get to the correct order set you want them to use.”

Making it easy was front of mind for the multidisciplinary team of physicians at Emory Healthcare who in 2017 implemented a reflex urine culture algorithm in three hospitals in the Emory network. In that intervention, the default inpatient urine culture order was replaced with an order set with two options: a prechecked order for urinalysis with microscopy, which reflexes to a urine culture if 10 or more white blood cells per high-power field are found, and a urine culture without a urinalysis (non-reflex urine culture). They kept the second option in the order sets for obstetric, neutropenic fever, neonatal, renal transplant, and pre-procedure urology patients, or for unusual circumstances in which clinicians wanted to order a urine culture directly. A retrospective study of inpatient urine culture rates before and after the order system intervention was put in place revealed a 47.2 percent reduction in the number of urine cultures ordered per 1,000 patient-days (Howard-Anderson J, et al. Infect Control Hosp Epidemiol. 2020;​41[3]:369–371).

New order interface updates that went live this October, when the health system transitioned its electronic medical record from Cerner Millennium to Epic, should make inappropriate urine testing still less frequent, Dr. Howard-Anderson says. “We want to make sure people are really thinking about ordering appropriate urine cultures. The new order set should make it easier to order the right test for the patient.”

With the new interface they’re providing more education on when patients should be treated for urinary tract infections, she says. “Just because a patient has pyuria and their urinalysis has enough white blood cells to meet the urine culture threshold doesn’t necessarily mean the patient has a UTI.” So in Epic, “the big new thing is you have to provide an indication for why you’re ordering even the urinalysis with reflex to urine culture. We didn’t require that in Cerner, so that will be the newest intervention.” The indications, which are presented as multiple-choice options, include UTI symptoms (urinary frequency, fever, or an obstruction of the urinary tract), septic shock, and spinal cord injury, with nonspecific symptoms such as bladder spasm, malaise, autonomic dysfunction, or fever. The option to proceed directly to urine culture, such as for those who are pregnant, remains with enhanced clinical decision support.

They plan to track whether the indications physicians choose when they order the reflex culture match up with the clinical information in the patient’s chart “to look for gaps in the current process and better understand the drivers of ordering urine cultures,” Dr. Howard-Anderson says.

Before the health system went live with Epic, Jesse Jacob, MD, MSc, senior author on the 2020 article and hospital epidemiologist at Emory University Hospital Midtown, spoke about the new order interface with the heads of hospital medicine services and critical care leads at all the hospitals. “He presented it to them and got their feedback,” Dr. Howard-Anderson says, noting that the inclusion of septic shock as an indication for ordering the reflex culture came out of those discussions. Conversations about how to optimize the order set are ongoing, she says. “So it’s an iterative process.”

New also are instructions within the order on how to collect urine cultures. These differ for patients who have urinary catheters, Dr. Howard-Anderson says. “If they have a urinary catheter and it’s been in for over seven days, the instructions are to remove the catheter, if possible, get a clean catch urine sample, and ideally not reinsert the catheter if they don’t need it anymore. If they do need it, it prompts providers to order the repeat catheter, and then they have to give an indication for the urinary catheter. So it’s trying to target both urine culture ordering as well as catheter use, wrapped up in the same order set.” They’ve also incorporated new educational support. “There’s a little bit of text about when urine cultures are not indicated,” she says. “We’re trying to educate people that a change in urine color, odor, or cloudiness shouldn’t be a reason to get a urine culture unless it’s paired with symptoms” or the other listed indications.

With the transition to Epic, hospital processes have been standardized across the health system, Dr. Howard-Anderson says, and the reflex algorithm now has been implemented across all hospitals in the network. They also have made a minor change to reflex criteria. The urinalysis now reflexes to a culture if 20 or more white blood cells are found, she says, a decision that came out of a quality improvement process in which charts of patients who had urine cultures were reviewed. In patients who had between 10 and 20 white blood cells in their urinalysis results and a positive urine culture, she says, “almost all of those cases were attributed to something other than a UTI.” With the 10 WBC threshold, then, unnecessary urine cultures still were being ordered. “In clinical practice when we see people with UTIs, they usually have greater than 150 white blood cells.” And in the chart review they didn’t find any missed UTIs in the 10 to 20 threshold range, she says.

Dr. Jacob and others worked with Epic on the order interface, Dr. Howard-Anderson says. “A lot of institutions use Epic and have thought about urine culture stewardship, and so there were some things that were already built. But they built this order set based on our specific requests, so it’s our own sort of homegrown Epic order set.”

The prechecked setting on the reflex urine culture order has been critical to the intervention’s ongoing success, Dr. Howard-Anderson says. “It’s what we call a nudge in terms of making something easier to do without restricting anything or significantly changing the choice architecture.” When a busy physician sees that the order for the reflex culture is already selected, they’re more likely to place the order, she says. It’s helped, too, that the reflex order is the first option to appear when physicians search for a urine culture. “Because people far and away are going to pick the first option.”

Some may be reluctant to use a prechecked setting, says David Murphy, MD, PhD, coauthor of the 2020 Infection Control & Hospital Epidemiology article and associate professor of medicine in the Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine at Emory. “We are often hesitant to set defaults because we recall the one in a hundred, one in a thousand patient scenario, and we need to have a robust enough system to account for those.” But those rare situations shouldn’t deter the use of default settings, Dr. Murphy says. “And in fact if we don’t set a default, we’re making the decision to provide no real guidance, and that’s problematic.”

Physicians are well aware that the standard urine culture should be ordered for some populations, such as pregnant patients, he says. And beyond the stated exceptions, “there certainly is room for variation,” he says. “Doing something 100 percent of the time for 100 percent of people is rarely the right thing to do.” If a patient has a history of resistant bacteria, for example, or if a patient is immunosuppressed in a way that’s not captured in the text of the order set, “clinicians at the bedside are going to understand those variations need to be made.”

Dr. Howard-Anderson and coauthors also reported a decrease in urinary tract infection diagnoses after the intervention went into effect in 2017. “A lot of institutions have implemented similar pathways in terms of having a reflex order set,” she says. “But we’re not aware of other studies that have looked at how that changes how clinicians are actually diagnosing patients and subsequently treatment.” She and her coauthors weren’t able to measure antibiotic use with the available data, “but we did see a modest but statistically significant decrease in the amount of UTIs diagnosed.” (The monthly median rate of UTIs/1,000 patient-days decreased from 16.1 to 14.7, for a potential monthly decrease of 49 UTIs.) By limiting urine cultures to patients with pyuria, “our hope is that people were more appropriately diagnosing UTIs.”