Our new BMJ-Evidence Based Medicine paper on Misleading Long Covid Studies
Out today in a new paper in the British Medical Journal - Evidence Based Medicine, Vinay Prasad, Shamez Ladhani and I argue these key points about Long Covid research:
The existing epidemiological research has suffered from overly broad case definitions and a striking absence of control groups. This has led to distortion of risk.
The unintended consequences of this may include, but are not limited to, increased societal anxiety and healthcare spending, a failure to diagnose other treatable conditions misdiagnosed as long COVID and diversion of funds and attention from those who truly suffer from chronic conditions secondary to COVID-19.
Future research should include properly matched control groups, sufficient follow-up time after infection and internationally-established diagnostic or inclusion and exclusion criteria.
The article was under embargo until today. I have been doing a number of press interviews including a radio interview I just finished with Stig Abell at Times Radio in London.
The people I have talked with in the press seem to agree this article will be controversial and ruffle feathers, even make people angry. This surprised me and made me go back and read it a couple more times. Why would aiming to accurately estimate the prevalence of and define (or create multiple subdefinitions of) “Long Covid” create such controversy?
I guess if it ends up 1/5 adult Americans don’t actually get long covid after their infection, like the CDC is telling us, there may be a risk of less funding for research of the condition. But should “long covid” really be defined as developing any of a long list of symptoms after your infection that last at least 3 months? Their online survey definition is absurd at face value; adults get new chronic health issues all the time. Why should we automatically attribute them to Covid? But CDC has not been much for accuracy lately.
To contrast with studies like the above from the CDC, we go over a number of more well-designed studies that have been reassuring in terms of their estimates of prevalence of lasting symptoms for those without critical illness. Two of my favorites are from Switzerland and Norway. Both look at children and measure antibodies rather than rely on positive tests (so catch asymptomatic cases) and both fail to find a significant difference in long covid prevalence between cases and controls (though the Norwegian study found covid+ kids were more likely to lose their sense of smell). These studies were too small to rule out really rare sequelae, though.
And none of us authors is suggesting people who feel they are suffering from sequelae of COVID-19 should not be taken seriously. As we say
“Ultimately, biomedicine must seek to aid all people who are suffering. In order to do so, the best scientific methods and analysis must be applied. Inappropriate definitions and flawed methods do not serve those whom medicine seeks to help. 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.”
Biased research has led to vast overestimates of the risks of developing long covid. The media and CDC have amplified the most misleading studies, leading to unnecessary anxiety and misdiagnoses, neither of which improve health. At the same time, those who may suffer from post-COVID sequelae may be marginalized, misunderstood and have less of a chance of receiving an understanding or truly effective treatment if every symptom under the sun can qualify as “Long Covid.”
Unfortunately this paper out today in Nature from the Putrino Lab had a very vague definition of what “Long Covid” is, so what are we to make of these “biological signatures”? Are they just alterations seen in people who feel unwell? Are they specific to a true “long covid” condition? I suspect the former.
Below are the inclusion criteria for the Putrino Lab study in Nature (see WHO criteria in our paper in BMJ EBM). This is the first part of their paper I read because, with this broad definition of long covid, we don’t know if they are studying something truly due to COVID-19 or just symptoms (“active symptomatology”) after covid infection, so why label it “Long Covid”?
We should all agree that accuracy is an essential part of being a compassionate physician. To that end, we created a guide for considerations when looking at existing long covid research and designing future studies.
Let us know… did you find inaccuracies in our paper? What do you agree or disagree with? There was no way to include every study on Long Covid, so which important ones do you think we missed?
I sense that the CDC is still looking for ways to illustrate the risk of getting COVID. Long COVID is one of those diagnoses that allow them to keep the hype high so they maintain another brick in the foundation for vaccines. I think we can all see that in the US especially there’s an truly inexplicable need to push the vaccines into the whole population regardless of age or health status. They need the hype. They need Long COVID as part of that fear machine.
In New Zealand I met people with 'long covid'. All are vaccinated with at least 3 Pfizers. Never had a positive Covid test. Diagnosis was done based on symptoms - shortness of breath after exercise, fatigue, lack of motivation. Thank you for you paper. Those people do need help, but first they do need a proper diagnosis.