In surgical services, stewardship steps reduce lab orders

Anne Paxton

February 2023—Consensus on the best ways to stem unnecessary laboratory testing, and spare health care systems and patients its negative effects, is still elusive. But a few years ago, when the team behind the University of Washington Medical Center’s Transforming Care Practice Initiative was looking for innovative ways to optimize the value of care provided within the health system, UW laboratory leaders saw an opportunity to collect new evidence on the proper role of laboratory stewardship.

“We realized we could study a more systematic approach by looking at a package of different interventions around laboratory stewardship,” says Patrick Mathias, MD, PhD, assistant professor and vice chair of clinical operations and associate medical director of the Informatics Division, Department of Laboratory Medicine and Pathology.

By measuring the outcomes of a multicomponent laboratory stewardship intervention on a defined patient population of surgery patients over a two-year period, the study team proposed to find out whether such a stewardship program could reduce laboratory testing without negative effects on patient care. The five components of the intervention were stakeholder engagement, provider education, computerized provider order entry modification, performance feedback, and culture change.

The findings are reported in a recently published study (Mathias PC, et al. Arch Pathol Lab Med. Published online Oct. 26, 2022. doi:10.5858/arpa.2021-0593-OA). The research team found that its stewardship intervention, as implemented with the UW Medical Center’s cardiac and thoracic surgery services, resulted in a decrease in laboratory test use—to the tune of 1.5 to two fewer tests ordered per patient day on each service. This amounted to an estimated 20,000 fewer tests performed across both services during the intervention period with no negative impact on length of stay, re­admis­sions, or mortality.

The research team chose to focus on interventions in the cardiac and thoracic surgery divisions because of their high use of laboratory testing, Dr. Mathias says. “We knew that awareness of laboratory stewardship was less prominent across surgical services,” he says. “It was clear that both cardiac and thoracic surgery had a significant amount of improvement that was possible. They were ordering laboratory testing very frequently—more frequently than some of the other surgery services.”

“The nice thing about the data is that we were able to monitor a couple of years before and a couple of years after the interventions,” Dr. Mathias says. The two years pre-intervention spanned January 2015 to Feb. 12, 2017, and the two years of intervention began Feb. 13, 2017 and ended in February 2019. The data source was a database that contains administrative, demographic, and lab use information.

The study is not as rigorous as, say, a randomized controlled trial, which is difficult to do in these contexts, Dr. Mathias says. “But it at least gives us some idea of how we can take the data and statistically scrutinize it to say, yes, there was a difference in these aspects before and after an intervention.”

Dr. Mathias and colleagues used the difference-in-differences analytic approach to compare intervention services to control surgical services caring for similar patient populations.

“There are approaches you can take that are less rigorous, looking at before and after. And I think the point of this is there needs to be more difference-in-differences analysis applied in these types of interventional studies in the laboratory setting.”

The multicomponent intervention study is not the first test of stewardship interventions at UW, Dr. Mathias says. The Patient-centered Laboratory Utilization Guidance Services program, known as PLUGS, was founded about 10 years ago at Seattle Children’s Hospital and has the aim of “helping our clinical colleagues select the best tests and better take care of their patients,” he explains.

That’s a concept that has long resonated with him. Late in his training as a clinical pathology resident at UW in 2014, he participated in a project led by Geoffrey Baird, MD, PhD, then director of chemistry at Harborview Medical Center (now chair of UW’s Department of Pathology and Laboratory Medicine), in which “internal medicine residents were essentially given report cards that included grades on how often they were ordering common tests like metabolic panels, CBCs, magnesium, and phosphate.”

For him, the main lesson of that experience was that there’s sometimes a culture of being on autopilot when ordering tests for inpatients. “Is that laboratory test really going to change how you manage the patient? Obviously, that should be a conscious decision. You may not want to miss a diagnosis of something for a patient, but there are many other cases where you order tests unnecessarily and by statistical chance it’s outside the reference range. Then you end up chasing down something that was not clinically meaningful. So you have to strike a balance,” he says.

The UW team studying the surgical services didn’t intend to do a thorough study at first. “It was going to be more around providing education and supporting our educational mission,” Dr. Mathias says. But before launching the study, he and the surgeon lead for the project, Farhood Farjah, MD, MPH, associate professor of surgery and associate medical director of the UW Surgical Outcomes Research Center, began to consider a set of simultaneous interventions. “The goal wasn’t necessarily to systematically study each individual intervention we put in place. It was more around what’s an effective collection of interventions that we can put together, that we can tailor to a service, and use to drive improvement in laboratory test ordering.”