Experts urge caution in rushing to define long COVID


While protracted COVID, also known as post-acute consequences of SARS-CoV-2 (PASC), is a rapidly emerging health crisis in the US and abroad, there is no practical medical definition for it — and that may not be a bad thing, said experts.

There are overarching definitions for long-term COVID, such as the CDC’s, which states that long-term COVID can be first identified “at least four weeks after infection”, and the WHO, which says it is “usually within three months of onset.” of the disease” occurs. COVID-19, with symptoms and effects lasting for at least two months.”

Medical associations have taken a more clinical turn in defining long-term COVID in an effort to improve patient care. The American Academy of Physical Medicine and Rehabilitation has listed 50 different symptoms that may be related to long-term COVID. Scrolling through patient-driven forums, such as the Reddit channel called r/covidlonghaulers, reveals an even more comprehensive list of symptoms.

Still, researchers and clinicians working to understand long-term COVID are no closer to identifying clear definitions for diagnosing or treating the condition. The absence of a well-defined algorithm for long-term COVID can be frustrating for doctors and their patients, but experts agree that rushing to define long-term COVID could present a whole host of new challenges.

Building blocks of a definition

According to Lawrence Kleinman, MD, MPH, of the Department of Pediatrics at Rutgers Robert Wood Johnson Medical School in New Jersey, we need to take our time defining long-term COVID, whether it be with a checklist, an algorithm, or an entry for the medical dictionary.

“If we defined it a certain way and we missed something in that first definition, then there will be silence until someone comes along and does a postmortem examination on our analysis,” Kleinman, who is also the principal investigator at the Rutgers pediatric hub of the NIH’s nationwide RECOVER study, MedPage today† “We want to avoid that as much as possible.”

He said more research and data collection is needed before the work of defining long-term COVID in a clinically meaningful way is possible. Right now, he noted, there aren’t even clear criteria for where to start.

For example, should researchers focus on setting a specific number of days for a person to experience fatigue after an acute COVID infection? If so, what should those ranges look like – fatigue after 30 days? As he noted, there isn’t enough data yet to develop the fundamental elements that researchers need to put together a practical definition.

Without those building blocks of data, such as the mechanism of fatigue associated with long-term COVID, researchers cannot begin to create definitions that can help clinicians diagnose and treat patients with those symptoms.

And they probably shouldn’t even try, said Sally Hodder, MD, of the West Virginia University Health Sciences Center. MedPage today

“I think the worst thing, especially when an entity isn’t understood, is to start making definitions that aren’t well grounded in science and exclude things that could actually be really important,” said Hodder, her university’s lead researcher. . adult hub of the RECOVER study.

Researchers now know a lot more about long-term COVID, but they also agree that it’s not the right time to rush to a specific clinical definition, in part because they’re still in the discovery phase — but that’s not all rode.

More complex than one definition

Another emerging insight into long-term COVID is the likelihood that it is more than just one syndrome. Walter Koroshetz, MD, director of the National Institute of Neurological Disorders and Stroke, emphasized that even the name “post-acute consequences of SARS-CoV-2” suggests plurality.

In fact, the experts who spoke to MedPage today agreed that it has multiple different phenotypes and endotypes. As such, researchers will need to focus on developing not just one definition, but multiple definitions, each with clinically relevant algorithms and guidelines to help clinicians work through each version of long COVID.

“They’re all important, but they’re all different,” noted Koroshetz, who is also the co-chair of the RECOVER Senior Oversight Committee.

According to David Putrino, PhD, the director of rehabilitation innovation at Mount Sinai Health System in New York City, the focus should be on identifying the endotypes of long-term COVID, including an immune-mediated type, a viral persistence-mediated type, and a chronic inflammation-mediated type.

In addition, he said he believes there are likely 10 to 15 different causes of long-term COVID, which is why it is critical to hold off on developing clinically meaningful definitions for the benefit of long-term COVID patients.

“I think given how difficult it is now to access adequate care, it is imperative that we keep the working definition of long-term COVID necessarily broad,” Putrino said. MedPage today

He noted that more specific definitions — which lack basic evidence — could lead to too much emphasis on patient presentation, which could hurt efforts to diagnose and treat as many patients as possible.

For example, using positive PCR tests or antibody tests to identify long-term COVID cases would likely lead to health inequalities, as people from historically disadvantaged groups do not have equal access to those tests.

Putrino also noted that antibody tests have not performed as well as expected and that some patients did not experience seroconversion with COVID-19. The bottom line is that a specific definition for even one endotype of long COVID would likely mean that large groups of patients will be left out of the guidelines or algorithms in the future, he said.

“Until we get all the endotypes under control, it would be an unmitigated disaster to narrow the scope of a definition,” he added.

Treatment without definition

While Putrino, along with several others, expressed concerns about defining long-term COVID, they also pushed for more data collection.

This is one area where doctors and their patients can make a meaningful contribution to building the knowledge base needed to ultimately develop clinical definitions for long-term COVID, Putrino said, recognizing that this has not been an easy task until now. One of his biggest concerns is time.

“The first interaction most people with long-term COVID have with medical professionals is with their primary care provider; their primary care provider has 15 minutes to work with them, which is just not nearly enough time,” he noted.

Putrino said he thinks that in order to provide long-term COVID patients with the care they need, and to improve broad data collection, primary care providers should be given more time — an hour before the first assessments of long-term COVID patients, rather than the default 15 minutes .

Diana Berrent, the founder of Survivor Corps, an advocacy and research organization for COVID patients, sees similar obstacles to improving treatment options for long-term COVID. She noted that the current status of the study does not allow for a patient-centered definition of these conditions, and that the medical community may still be unaware of all the possible symptoms of long-term COVID.

Like Putrino, Berrent said the focus right now should be on working with long-term COVID patients.

“I think there needs to be a greater urgency focused on providing aid, while at the same time seeking to define and identify the mechanisms of the upstream causes of these problems,” she said. “People are losing hope.”

Putrino stressed that the risks of limiting the definition would be placed entirely on patients who struggle to receive proper care to treat their unique symptoms. A definition that excludes even a small number of patients would be a critical flaw in the effort to address this crisis, he said.

“What we should do now, given how difficult it is to get care, is that we must necessarily keep the definition broad,” he stressed. “We should count everyone, and we should say this is the number of people across the country with persistent symptoms.”

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    Michael DePeau-Wilson is a reporter on the MedPage Today enterprise and research team. He covers psychiatry, long-term covid and infectious diseases, among other relevant clinical news from the US. Follow

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