Striking the Right Balance With Molecular Diagnostics Usage and Stewardship

With the emergence of molecular rapid tests, clinicians have more diagnostics at their disposal. However, these tests can be costly and may not result in better outcomes. Timothy Jenkins, MD, medical director, of the antimicrobial stewardship program, and the microbiology laboratory at Denver Health, who spoke at a session at ID Week looking at diagnostic stewardship talked about some of the ongoing issues with molecular diagnostics today. He explains there are scenarios where unnecessary tests are being conducted that can be costly, identify viruses that do not change treatment management, and done at the wrong time of year.

For example, Jenkins said they have implemented a diagnostic pathway with specific criteria for broader testing for diarrheal illnesses at his institution, Denver Health.

“Patients with more severe illness—hospitalized or large number of stools per day, or high fever, patients who have had persistent symptoms for a week or more, or who may be immunosuppressed—those are appropriate indications to get one of these broader PCR panels,” Jenkins said. “We embedded those indications within the order in our electronic health record, so providers have to check which of those indications their patient has for why they're testing. And if they don't have any of those indications, then they get a message or an alert that says testing may not be indicated in this patient."

"Most diarrheal illnesses are mild and self-limited, and your patient may not need a test, and we also provide the cost of the test...These are very high-cost tests, and a lot of our providers said we want to know how much these test costs when we're ordering them. So, we were very transparent with the cost of the test...so that providers knew and could take that into account in their decision making of whether to order the test.”

Jenkins says this intervention has resulted in approximately a 25% reduction in this type of testing.

For respiratory illness, he says Denver Health has developed a few different stewardship approaches. Across the different settings including the hospital, emergency department, and urgent care settings, they had been employing broader respiratory PCR panel that tested for many different targets, but this did not change their patient management approach. As such, they developed an intervention asking providers to no longer use that test routinely, but to use it in a much more select clinical scenario.

“We actually removed the order from our electronic health record so that providers have to request approval from an infectious disease provider or the lab to use it. And that's really markedly reduced use of that test by by more than 90%,” Jenkins said. “That really reflects more clinically appropriate use of that test. At the same time, we're recommending use of influenza and Covid PCR tests. We want to make sure that we're using those in the right scenario. And so a lot of our guidance has been around the CDC universal respiratory isolation guidance that you don't need to test to inform outpatient isolation practices.”

Another aspect they have changed is the time of year for virus testing. For example, he said they have been testing for influenza and RSV throughout the year and he points out that these viruses do not circulate in the summer.

“We had done more than 3,000 of these tests over the summer...So we again implemented an intervention where we removed the order from the electronic health record during the summer. So, from June to the end of September—when those viruses are not circulating—and communicated this widely to our providers and said, 'if you have a high suspicion for influenza in a particular case, you can call the lab and request the test.' So it's still available to you; it's just not available to be easily ordered in the electronic health record."

He said this intervention alone has caused an approximately 99% reduction in these tests during the summer months.