A laboratory algorithm that cancels redundant same-day white blood cell (WBC) differential orders saves money and technologists’ time, according to new research.
The findings suggest that employing such a program is “a simple and sustainable way to achieve lasting improvements to laboratory utilization” while also being acceptable to clinicians, write Kristine Roland, MD, a hematopathologist at Vancouver General Hospital (VGH) and a clinical associate professor of medicine at the University of British Columbia, and colleagues.
The research was published in the April 2022 issue of the American Journal of Clinical Pathology.
The algorithm was born out of an effort to reduce unnecessary medical testing at VGH that was inspired by the Choosing Wisely Initiative, launched in 2012. The initiative, led by the American Board of Internal Medicine Foundation, advocates avoiding overuse of tests and medical procedures. At VGH, a complete blood count (CBC) is available with or without a WBC differential, but the CBC with WBC differential (CBCD) is more frequently ordered. CBCD uses more reagents than a CBC alone and generally does not need to be repeated in a 24-hour period. “It was just being ordered because it was there,” said Roland in an interview with Medscape Medical News. “[Clinicians] didn’t really need it.”
Using the middleware software Data Innovations Instructions Manager, Roland and team implemented a policy of automatically canceling redundant same-day WBC differential orders. While the results of the first CBCD order that day were available, any additional same-day orders had the comment, “See previous differential,” in place of the results. If a repeat CBCD was necessary, a clinician could call the lab to request that an additional WBC differential be performed. Patients undergoing autologous stem cell collections were excluded from the policy, because at VGH, repeat WBC differentials after stem cell collection are required as a part of quality assurance. After a trial period in the intensive care unit beginning September 25, 2019, the algorithm was implemented hospital-wide on March 23, 2020.
To see how the algorithm performed in canceling WBC orders and saving lab costs, Roland and colleagues evaluated WBC differential cancellations during the ICU postimplementation period (October 1, 2019, to February 28, 2020) as well as the hospital-wide postimplementation period (April 1, 2020, through December 31, 2020). The team calculated the proportion of canceled differentials per month to account for the total reduction in CBCD orders during the early stages of the pandemic.
From September 25, 2019, to December 31, 2020, 10,195 WBC differentials were canceled. Of the 4717 unique patients for whom differentials were canceled, for most patients, only one order was canceled. Only six canceled differentials were reactivated, three of which were from autologous stem cell collections and were canceled in error. The remaining three repeat differentials were requested by the ordering physician. All three patients were diagnosed with acute myeloid leukemia. The monthly WBC differential cancellation rate was 5.4% (959 differentials canceled) per month from April 1, 2020, to December 1, 2020.
The team estimated that each canceled differential saved $0.99 Canadian dollars ($0.77 US dollars) and that during the 15-month postimplementation period, the algorithm saved 1060 minutes (17.7 hours) of technologist work time.
Part of the algorithm’s success is that it required no additional effort on the clinician’s or lab technologist’s side, Roland said. This differs from many other interventions that focus on education to reduce unnecessary test ordering.
Initiatives that focus solely on education or on behavior change have generally been found to be ineffective, Geoffrey Baird, MD, PhD, a professor and chair of the Department of Laboratory Medicine and Pathology at the University of Washington School of Medicine in Seattle, told Medscape. The rotation of new residents, medical students, and other trainees at a hospital every year make it difficult for an educational initiative to have a long-term effect, he said. “The literature is strongly suggestive that the best interventions are those that are hardwired, meaning an algorithm or some change to an order set,” he said.
Baird noted that while the estimated cost savings are not large, “every dollar does count.” There may also be additional downstream savings not captured in the study, such as through not ordering additional tests or treatments on the basis of changes in repeat results. While in some cases, detecting these changes is helpful for treatment, that largely doesn’t apply for repeat same-day WBC differentials, he added. “I think almost all involved in the practice of medicine would agree that it was probably duplicative and not terribly helpful,” he said.
Roland said she hopes that her findings showcase the value of using technology to improve efficiency in laboratory testing. “I think it really is the wave of the future,” she said, and while implementing these technologies, such as middleware software, has upfront costs, “if you use it to its full advantage, then you can achieve real savings and efficiencies.”
Baird started the company Avalon Healthcare Solutions, which provides laboratory test utilization management for health insurance companies. He serves on the company’s clinical advisory board. Roland reports no relevant financial relationships.