Long COVID risks are 'distorted by flawed research', study finds

The risk of contracting long COVID may have been exaggerated due to flawed research, leading to unnecessarily high levels of anxiety about suffering from it, a new study has suggested.

"Major flaws" in the literature on the condition likely exaggerated the true threat of contracting it, the new research argues.

Fatigue, brain fog, chest pain and shortness of breath are reported as symptoms by those who have long COVID – which is officially known as post-acute sequelae of COVID-19.

Now, researchers from the UK, along with Denmark and the USA, say "Many scientific publications" overestimated the prevalence of long COVID because of "Overly broad definitions, lack of control groups, inappropriate control groups, and other methodological flaws".

The study argues none of the definitions "Requires a causal link" to COVID-19 infection, adding any symptoms that happen after a confirmed or suspected infection could be considered consistent with long COVID. "In general, in the scientific literature, imprecise definitions have resulted in more than 200 symptoms being associated with the condition termed long COVID," the researchers said.

Research in the future should include properly matched groups, the paper added, as well as "Sufficient" follow-up time following infection.

"Ultimately, biomedicine must seek to aid all people who are suffering," the research team added.

"Improving standards of evidence generation is the ideal method to take long COVID seriously, improve outcomes, and avoid the risks of misdiagnosis and inappropriate treatment.”

"Long COVID simply didn't exist four years ago, so researchers have had to get to grips with a new and challenging topic at top speed.”

"It is not surprising that different studies have different estimates of the prevalence of long COVID, as studies have used different case definitions, different populations etc.”

Dr Jacobs said a survey by the Office for National Statistics, which was discontinued in March, found that 1.9 million people in the UK had long COVID. He said this was a "Staggeringly high" number.

"We don't know how long those people will remain ill," he added.