Clinical laboratory teams around the world face the ongoing challenge of aligning their testing protocols with the goals of diagnostic stewardship. The idea is to ensure that every test provides actionable data to inform patient care and that unnecessary testing is kept to a minimum.

Molecular testing—including both centralised laboratory assays and point-of-care (POC) tests—is an important component of any diagnostic stewardship programme. This is especially true for respiratory testing, where POC tests can help ease the burden on hospital laboratories during seasonal peaks in demand and deliver faster answers with easy-to-use technology for emergency departments.

Now that the World Health Organization no longer considers COVID-19 an international public health emergency, clinical lab leaders in health systems across Asia are working to establish new respiratory testing algorithms that incorporate SARS-CoV-2 into routine protocols as needed.

To learn more about how this could work in a healthcare system, Lab Insights sat down with Prof Chien-Chang Lee, a Professor of Emergency Medicine at National Taiwan University Hospital who is currently developing new guidelines for respiratory testing in emergency departments.

Protocols for COVID-19, RSV and flu testing

In Taiwan, the concept of diagnostic stewardship fits well into the government’s unique reimbursement system. This includes very strict criteria for testing and financial penalties for hospitals that use tests inappropriately. The benefit of each test must be very clearly defined to ensure that physicians order the right test for each situation.

Prof Lee aims to establish guidelines for evidence-based laboratory medicine, which would rely on solid scientific evidence to enable selection of the most appropriate test. This would allow physicians to “order any test they want — as long as they can justify it,” he says.

For suspected respiratory infections, Prof Lee has evaluated various protocols for ordering COVID-19, respiratory syncytial virus (RSV), and flu tests. For most patients, a rapid antigen test for COVID-19 would be the first option; it’s less expensive and can be used virtually anywhere. Molecular testing is considered the second-line option for patients who are at higher risk, such as those with a prior history of COVID-19 or who are in poor health. Having highly accurate molecular results for these more vulnerable patients is appropriate because it makes it easier to match them to needed treatments. The rapid results of molecular tests are essential as well: patients who need antivirals have better outcomes when they start treatment sooner. Within the emergency department, the speed and ease of POC testing ensures that patients get the right treatment recommendations quickly.

RSV testing also varies by population. It is very common in the paediatric context, but growing awareness has increased demand for testing adults as well, especially now that doctors know RSV can be fatal for elderly patients with haematological conditions. Testing can also help guide appropriate treatment selection, avoiding overuse of antibiotics. At the moment, Prof Lee says, RSV testing is not routinely used in Taiwan but he hopes to change that based on the prevalence of these infections and the usefulness of test results for clinical care decisions.

For influenza testing, Prof Lee points to the challenge that molecular tests often cost more than basic antiviral drugs. Even though drugs can often be prescribed based solely on clinical signs and symptoms, he adds, the pandemic helped educate physicians about the value and accuracy of molecular tests. There is now a push to incorporate these tests when possible to distinguish between flu and other respiratory infections so that the most appropriate treatment can be prescribed.

Considering the costs…and benefits

In the past, it had been challenging to justify the costs of a molecular test for viral respiratory infections in Taiwan because most viral pathogens cannot be treated with medications, Prof Lee notes. As more and more antiviral treatments come to market, though, the clinical value of testing will be easier to demonstrate. There’s also economic value: “If you can save one day of hospitalisation or two days of antibiotics, then the cost of a molecular test is justified,” he says.

Both clinical and economic value will be important elements of establishing new guidelines for respiratory testing in Taiwan and elsewhere. Rapid antigen testing is targeted and cheap, but not always highly accurate. Broad syndromic testing may be overkill for many patient situations. A middle ground of targeted molecular testing—including both centralised options and POC tests for emergency department use—could be the ideal way to bring respiratory testing in line with diagnostic stewardship goals.