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AMP Panelists Highlight Need for Careful Lab Stewardship of Infectious Disease MDx

NEW YORK – Molecular diagnostics are powerful tools for tackling infectious disease, but laboratories need plans in place to help manage use of these tests, a panel of clinicians suggested at this week's annual meeting of the Association for Molecular Pathology.

In a roundtable discussion, Neil Anderson, assistant medical director at Barnes Jewish Clinical Microbiology Laboratory; Jane Hata, director of the clinical microbiology and serology laboratory at the Mayo Clinic in Florida; Amanda Harrington, director of the clinical microbiology laboratory at Loyola University Medical Center; and Daniel Diekema, director, division of infectious diseases at University of Iowa Health Care tackled the stewardship challenges presented by the increasing uptake of molecular testing for diagnosing and managing infectious diseases.

Eliminating overuse and controlling costs was a major discussion point given the relatively high price tags of assays like syndromic respiratory panels, but the panelists also highlighted the role of clinical labs in helping doctors make the best use of these tools and developing procedures for reporting results that will best impact patient care.

Diekema suggested, in fact, that for all the advances in infectious disease molecular diagnostics, in many cases their impact in terms of improving patient outcomes remains unclear.

"These are amazing technologies that we have now… but it's been really, really difficult to demonstrate that they have even an impact on management, much less an impact on outcomes," he said, adding that one of the reasons for this is that conventional testing is by and large quite powerful.

"It's a very, very high bar to develop a test that is going to be more sensitive, or accurate, faster, more precise," he said.

This basic fact should inform usage of these tests and laboratories' conversations with physicians around ordering, Diekema said. "If someone wants to send out for broad-range PCR or metagenomic testing, [the lab should] really start that conversation and say, well, what are you really suspecting here?"

He added that this would both help clarify the utility of the advanced molecular diagnostics while also remind doctors of the power of conventional diagnostics.

Anderson similarly noted that the perceived power of molecular testing made it a tool doctors are perhaps overly quick to reach for, particularly when trying to rule out conditions.

"We get a specimen in the lab and it says, I want culture, I want every PCR under the sun, and then I want you to send it for broad-range [PCR]," he said. "And then when we push a little harder and we ask why, it's like, well, we aren't really even sure it's an infection. We just want to rule out infection and be able to treat this patient with steroids or whatever."

"I think now that providers know these tests exist… they are being viewed by some anyway as a necessary component of a patient rule-out, and I think that needs to be redefined and discussed with providers," he added.

The issue isn't just one of test over-usage and cost, Anderson said. There is also the fact that a test like broad-range PCR might not be as sensitive as a more targeted approach, limiting its utility as a rule-out tool.

Harrington said that her lab has had success in steering doctors away from moving immediately to molecular approaches and encouraging them to try more traditional tests first.

"Maybe they want that high-powered tool as option one, and maybe it could be backed up to option four," she said. She added that providing assurance the molecular tools would be there if needed had been key to convincing providers to start with conventional testing.

"We've been able to steer a lot of utilization [away from molecular as first option] just by giving people the confidence to wait," Harrington said.

Hata said her lab has taken to laying the groundwork for more careful utilization when medical residents or fellows come through the lab during their training.

"I spend a little extra time in the molecular section and in addition to talking about what it is and how it works I get into, this is a powerful tool and always ask yourself why are you doing this and what are you going to do with the result be it positive or negative," she said. "I think just that little bit of time you spend with them plants a seed and hopefully makes them think down the road as they are ordering or not ordering these tests that they will do it with the appropriateness in mind."

Then there are the more formal approaches to molecular diagnostic stewardship. Anderson noted that at Barnes-Jewish his lab has a list of tests that it will not provide until the ordering doctor has discussed it with the lab.

Diekema said that at Iowa his lab keeps a clinical microbiology resident on call who is involved in any decisions to send out for advanced molecular testing. Harrington said Loyola likewise has a process in place for reviewing molecular test orders.

Ongoing consolidation within the lab and healthcare industry has complicated the stewardship process, Anderson said, noting that his lab does testing for a number of St. Louis-area hospitals both in and outside the Barnes-Jewish system.

While a particular hospital may have well-established practices around test ordering, other hospitals may have different ordering practices, both for good and bad reasons.

"What I have learned from the process is that you have to tread very lightly," Anderson said. "You know what is good practice in your hospital, but you have to understand that it's a different hospital, it might have different patient populations, and there are certainly some things you really need to look at."

He said that during the consolidation process, Barnes-Jewish established expert groups in microbiology and the other areas where it was consolidating and had in-depth meetings to try to identify and resolve potential conflicts. Having such groups make formal decisions around these questions was also useful in that it provided a source of authority labs are able to point at to support their decisions and policies in the future.

Diekema said he and his team were discussing establishing more formalized decision making processes for this reason.

"A lot of these decisions are sort of made more ad hoc and with continuous ongoing input from [the infectious disease department] and our lab and some of our folks in stewardship and infection prevention," he said. However, he noted, "after getting yelled at by urologists for 30 minutes because they want metagenomics on every urine [sample], it sort of stimulates you to think, yeah, we could probably use that kind of backup."

Systems, electronic and otherwise, for reviewing tracking test usage are also key, Anderson said, noting that his facility had found that tools for alerting physicians as they are ordering are particularly useful.

"We've actually started building into a lot of our tools [capabilities] where basically you say, you're ordering flu-RSV, you just ordered a flu-RSV yesterday," he said, adding that when his team looked at patterns of repeat testing it found that for respiratory virus testing in particular many repeat orders came in before the results from the original order had been returned.

"That's clear just miscommunication," he said. "So if you can communicate with them and say in an alert something like, 'Hey this test is still pending,' or 'This test was positive yesterday, are you sure you still want it?' the provider might be like, 'Oh, great, I got the result I was looking for without having to wait.' It makes everyone happy."