While some aspects of long COVID-19 — sometimes referred to as post-COVID-19 condition, or PCC — are much better understood than before, researchers have yet to land on a unified definition for the condition.
Around 10 percent of individuals who experience COVID-19 infections are at risk for also contracting long COVID to some degree. The prevalence of the condition prompted the Biden administration to call for extended research into it in April 2022.
However, the major complications around research on the condition relate both to its various names and broad references to a collection of different symptoms after a coronavirus infection, which "makes assimilating and comparing findings from current studies difficult," U.K. researchers Daniel Pan, MD, and Manish Pareek, PhD, wrote in an April 5 report published in JAMA.
The researchers argue that if the condition is universally defined, more effective treatments for it can then be developed. They say working toward this consistency can be accomplished in three parts.
Their proposed definition to build a framework for unifying dialogue around long COVID is "signs and symptoms following initial SARS-CoV-2 infection, that persist for more than one month (in mild cases), and more than three months (in cases severe enough to warrant oxygen support), which have a disproportionately severe effect on a patient’s quality of life, far beyond what is expected from their initial infection." Researchers also wrote that sticking to the term "long COVID" makes more sense since it was the first term used to describe the condition.
Additionally, they suggest that studies on long COVID should be inclusive of high-risk populations, be diverse and account for individuals who may be unknowingly experiencing long COVID's effects as well.
Longitudinal studies that look at the effects of long COVID must also involve patients who experienced it but did not have substantially profound symptoms that altered their daily lives, they suggest.
"These studies must have one unified definition and title of the same syndrome, that is agreed on by patients, clinicians, and academics alike, and have the potential to identify different disease phenotypes," researchers wrote. "To treat PCC, we must first develop better studies that can identify what PCC actually is. Only then can we have a more personalized and effective approach to the treatment of those affected."