As pandemic-era practices give way to more tailored strategies, laboratories are reconsidering how much respiratory testing is appropriate for different patients and clinical situations.

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By Alyx Arnett

(Editor’s note: This article is part of an ongoing series sponsored by Diasorin examining the changing respiratory testing landscape and the range of options available to laboratories.)

More than six years after COVID-19 drove rapid changes in respiratory testing, clinical laboratories are reassessing the strategies they built or expanded during the pandemic. As pandemic-era testing volumes have subsided, laboratories are reconsidering who benefits from broader testing, which results meaningfully affect patient management, and how to support the medical necessity of their testing pathways.

Laboratories are making those decisions amid unpredictable pathogen circulation, sustained financial pressure, and growing attention to diagnostic stewardship. Two recent studies show how health systems are changing their respiratory testing practices. One reported a 96.4% reduction in use of a 22-target respiratory pathogen panel after the health system adopted a selective testing strategy.¹ The other estimated up to $2.26 million in reagent savings after implementing clinical decision support that guided clinicians toward a smaller respiratory panel when appropriate.²

“During the pandemic, the priority was access, speed, and capacity,” says Stephanie Ibbotson, Senior Director of Market Access at Diasorin. “Laboratories needed to test large numbers of patients quickly, often under extraordinary uncertainty. That environment accelerated the adoption of multiplex testing, but it did not always allow time to build differentiated testing pathways around patient type, care setting, or clinical need.”

The question laboratories are asking now, she says, is whether every patient needs the same amount of information—and whether that information changes care.

From Detection to Decision

Ibbotson describes the current period as a move “from the value of detection to the value of the decision enabled by detection.” She points to three reasons: changing respiratory epidemiology, tighter healthcare budgets, and increasing scrutiny of clinical utility.

COVID-19 changed how respiratory viruses circulate and how health systems prepare for respiratory demand, Ibbotson says, noting that laboratories can no longer assume a predictable winter season or rely exclusively on national trends. At the same time, laboratory leaders are being asked to justify not only whether a test performs well but also whether it is being used in the right population and whether the result changes treatment, isolation, admission, or another meaningful decision.

Kaisha Gonzalez, PhD, MB(ASCP)^CM, Regional Director of Scientific Affairs at Diasorin, agrees that “recalibration” captures the current landscape. “SARS-CoV-2 is now one of several respiratory pathogens laboratories routinely have to consider, respiratory circulation patterns continue to shift, and testing volumes are no longer being driven by the same pandemic-era circumstances,” she says.

Together with staffing limitations, cost pressures, and reimbursement scrutiny, those changes are prompting laboratories to reexamine strategies built or expanded during the pandemic.

Laboratories also have more testing options and more utilization data than they did during the pandemic, Gonzalez says.

 “We have targeted assays, different sizes of multiplex panels, and increasingly flexible approaches, which creates an opportunity to be more deliberate about the testing strategy rather than applying the same approach across every population or setting,” she says.

Utilization, positivity, clinical utility, and local pathogen data can help laboratories periodically reassess their strategies instead of relying on the same approach year after year.

Tiered Testing and the Limits of a Single Approach

Ibbotson and Gonzalez describe growing interest in differentiated or tiered testing strategies that match the breadth of testing to the patient, care setting, and clinical question.

According to Ibbotson, a small panel may be appropriate for a lower-risk outpatient when the primary question is influenza, RSV, or COVID-19. A broader panel may be more appropriate for an immunocompromised or critically ill patient, or for someone with an atypical presentation for whom identifying the pathogen could materially alter management. The challenge, she says, is that many laboratories have built workflows around fixed panels and multiple platforms and may lack the flexibility to implement a more tailored approach without adding complexity.

Gonzalez points to newer testing formats that can support differentiation without requiring laboratories to move among multiple platforms.

“Traditionally, changing the breadth of testing often meant moving between different assays or platforms with predefined content,” she says. “Flexible syndromic testing introduces the ability to select individual targets within a multiplex testing strategy. That allows laboratories to think about testing at the target level rather than only choosing between fixed panel sizes.”

Gonzalez says greater flexibility could make it easier to tailor testing to differences in clinical need. Clinical need exists on a continuum, she says, while laboratories have traditionally had to translate those differences into a limited number of fixed choices. Still, she cautions that panel size alone is not a useful measure of appropriateness.

“The more relevant consideration is whether the pathogens being tested are appropriate for that patient and whether identifying them can contribute meaningfully to management,” Gonzalez says.

That approach is consistent with 2024 guidance from the Association for Diagnostics & Laboratory Medicine.³ The guidance recommends considering clinical presentation and local prevalence and testing when results are expected to affect patient management or infection-control decisions. In general, it recommends using targeted nucleic acid amplification tests or small multiplex panels first when available, while recognizing a role for broader multiplex testing in immunocompromised and other higher-risk patients.

Reading the 2026 Stewardship Studies

The two studies behind the 96.4% reduction and $2.26 million savings figures show how health systems are moving toward more selective testing. But Ibbotson and Gonzalez say the numbers require context.

In the first study, an academic safety-net health system replaced unrestricted use of a 22-target respiratory pathogen panel with a selective testing strategy.¹ The broader panel generally remained available after influenza, RSV, and SARS-CoV-2 had been excluded and when identifying another pathogen was expected to influence management or provide necessary diagnostic certainty.¹ Median weekly use fell from 83 tests to three—a 96.4% reduction that was sustained for one year. Annualized laboratory costs associated with the panel fell from $741,446 to $30,623.¹

Ibbotson, who was not involved in the research, says those findings are compelling, particularly for health systems seeking immediate savings, but the lesson is not simply that laboratories should use fewer broad panels.

“The real lesson is that testing needs to be segmented,” she says. “Both studies demonstrate the value of building criteria around which patients need broader testing. They do not establish that broad panels lack value in immunocompromised, critically ill, pediatric, or diagnostically complex populations.”

Gonzalez, who also was not involved in the research, points to important changes in who received the broader panel after the intervention. The median patient age fell from 50 to 7.5 years, and children accounted for approximately 60% of patients tested, compared with 16% before the intervention.¹ Although the overall positivity rate remained similar—32.1% before the intervention and 35.9% afterward—the distribution of pathogens detected changed.¹ The study was also conducted within a single health system and did not evaluate the intervention’s effects on clinical outcomes.

The second study examined a clinical decision-support tool implemented across six Penn Medicine hospitals.² When clinicians initiated an order for a larger respiratory pathogen panel, the system presented a four-target seasonal respiratory viral profile as the default. Clinicians could still select the larger panel after documenting an approved indication or entering another clinical justification. Compared with the preintervention trend, the intervention was associated with an estimated 18,800 fewer large-panel orders and approximately $1.88 million to $2.26 million in reagent savings.²

In reviewing the published findings, Gonzalez cautions that the estimate covered reagent costs only—not total healthcare costs or clinical outcomes. Ibbotson says those unanswered questions are important when determining whether a new testing pathway has created value.

“Did the intervention affect length of stay, antimicrobial use, repeat testing, isolation, missed diagnoses, or downstream utilization?” she asks. “Those outcomes will ultimately determine whether the new pathway created value or simply reduced one category of spending.”

Balancing Overtesting and Undertesting

Diagnostic stewardship conversations often center on overtesting, but Ibbotson and Gonzalez say laboratories must also account for undertesting.

“Overtesting creates visible costs: higher reagent use, more denials, and results that may not change management,” Ibbotson says. “Undertesting can create less visible but equally important costs, including repeat testing, empiric treatment, delayed diagnosis, longer isolation, and extended length of stay.”

The health system in the selective-use study adopted the intervention after an internal review found frequent broad-panel testing among low-risk patients in ambulatory settings, little apparent effect on clinical decision-making in ambulatory and inpatient settings, and substantial laboratory costs.¹ Yet the broader panel remained available for selected cases in which clinicians believed the results could provide additional value.

Those cases included situations in which identifying a pathogen could potentially avert an invasive procedure, such as a lumbar puncture in an infant or bronchoscopy in a critically ill adult, or inform treatment or infection-prevention decisions.¹ The study documented clinicians’ rationales for ordering the panel but did not determine whether testing ultimately averted procedures or changed treatment or infection-prevention decisions.¹

Gonzalez says deciding between targeted and broader testing depends heavily on the patient. Targeted testing for the most clinically relevant pathogens may be sufficient for an otherwise healthy outpatient with uncomplicated symptoms. In an immunocompromised patient, however, the differential may be broader, and identifying additional pathogens may have greater implications for treatment, infection control, or further diagnostic workup. Pediatric populations can also have a different distribution of respiratory pathogens, she adds, making targets that contribute little in one population more relevant in another.

“I would be cautious about defining successful stewardship simply by reducing the number of targets tested,” Gonzalez says. “The objective is not necessarily to test for fewer or more pathogens, but to make sure the testing strategy provides the information that is appropriate for the patient and the clinical question.”

Reimbursement, Documentation, and the Payer Question

Reimbursement is increasingly difficult to separate from respiratory testing strategy, particularly in outpatient settings. Coverage can depend on the number of pathogens included, the patient’s condition, the care setting, and the Medicare contractor or commercial payer reviewing the claim.

Medicare’s local coverage determinations (LCDs) provide one example. Under one LCD, Part B outpatient coverage is limited to panels containing five or fewer pathogens, and the result must be available in time to aid clinical management.⁴ Panels containing more than five pathogens are considered not medically necessary under that policy.⁴ A separate MolDX policy allows limited coverage of expanded respiratory panels when targeted testing is not appropriate and additional criteria are met.⁵ Depending on the patient, those criteria may include immunosuppression, critical illness, severe underlying respiratory disease, treatment in a critical care setting, or ordering by an appropriate specialist.⁵

The related Medicare billing guidance also requires the medical record to support the ICD-10-CM code submitted and demonstrate that the test could contribute to clinical management and an improved health outcome.⁶

Ibbotson says similar distinctions appear across payer policies, with expanded testing often requiring evidence that a smaller panel would not provide enough information to manage the patient appropriately. The problem, she says, is that test selection, clinical documentation, coding, and payer requirements are not always aligned. A laboratory may perform an appropriate expanded panel only to see the claim denied because the medical record does not explain why broader testing was necessary.

Gonzalez says recurring denials can themselves serve as a signal. “If a laboratory is seeing recurring denials for particular testing scenarios, that can identify areas where ordering practices, documentation, or the testing pathway itself may need to be reviewed,” she says.

Gonzalez and Ibbotson emphasize that reimbursement should not determine clinical appropriateness, but it cannot be ignored when laboratories evaluate whether a testing strategy is financially sustainable.

The Full Cost of an Answer

The price of an assay does not show what respiratory testing ultimately costs a laboratory or health system. Ibbotson and Gonzalez say laboratories should evaluate the entire testing pathway rather than compare assays based solely on price.

Within the laboratory, Ibbotson says, that includes staffing, hands-on time, quality control, validation, inventory expiration, platform maintenance, repeat testing, send-outs, denials, and the cost of supporting multiple assays. Health systems should also consider what happens after the result, including antimicrobial use, isolation, additional testing, length of stay, and clinician follow-up.

“A lower-cost targeted test is not necessarily less expensive if a negative result leads to two additional tests,” Ibbotson says. “Conversely, a broad panel does not automatically create value simply because it produces more information.”

The better question, she says, is: “What is the total cost of reaching a clinically useful answer?”

Gonzalez points to platform complexity as another frequently overlooked expense. Offering different levels of respiratory testing can require laboratories to maintain multiple assays, instruments, inventories, quality-control processes, staff competencies, and service requirements.

“Those operational costs are easy to overlook when comparing assays based only on reagent price,” she says.

Preparing for the 2026–27 Season

As laboratories prepare for the coming respiratory season, Ibbotson and Gonzalez say they should be ready to adjust testing as patient needs and pathogen activity change.

Ibbotson says laboratories should move from a test-menu strategy to a patient-segment strategy, identifying which populations need targeted testing, which need expanded testing, and what clinical or operational criteria should trigger escalation. Laboratories should also monitor local pathogen activity, test utilization, payer policies, and denial trends throughout the season rather than waiting for an end-of-year review.

Gonzalez adds that laboratories should stay current on changes in clinical guidance, reimbursement, and medical-necessity requirements that could affect how respiratory testing is used.

“A testing strategy that makes sense during peak winter activity may not necessarily be the most appropriate approach as pathogen circulation changes later in the season or into spring and summer,” she says. “Local data can help identify when those shifts are occurring rather than relying only on a predetermined calendar.”

Success will not necessarily depend on offering the largest or smallest panels, Ibbotson says. It will depend on being “capable of matching the level of testing to the patient while demonstrating the clinical, operational, and economic value of that decision.”

References

1. Jenkins TC, Young HL, Wyles DL, et al. Effects of a diagnostic stewardship intervention to de-implement widespread use of a rapid respiratory multiplex PCR test. Microbiol Spectr. 2026;14(9):e0036426.
2. Flores EM, Li Y, Reece JT, et al. Health system implementation of clinical decision support to optimize respiratory pathogen profile utilization. J Clin Microbiol. 2026;64(8):e0190925.
3. Berry GJ, Jhaveri TA, Larkin PMK, et al. ADLM guidance document on laboratory diagnosis of respiratory viruses. J Appl Lab Med. 2024;9(3):599-628.
4. Centers for Medicare & Medicaid Services. Local coverage determination: respiratory pathogen panel testing. Accessed 2026 Sept 2.
5. Centers for Medicare & Medicaid Services. Local coverage determination: MolDX: molecular syndromic panels for infectious disease pathogen identification testing. Accessed 2026 Sept 2.
6. Centers for Medicare & Medicaid Services. Billing and coding: respiratory pathogen panel testing. Accessed 2026 Sept 2.

Photo credit: Diasorin

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