Course of post COVID-19 disease symptoms over time in the ComPaRe long COVID prospective e-cohort, 2022, Tran et al

Abstract

About 10% of people infected by severe acute respiratory syndrome coronavirus 2 experience post COVID-19 disease. We analysed data from 968 adult patients (5350 person-months) with a confirmed infection enroled in the ComPaRe long COVID cohort, a disease prevalent prospective e-cohort of such patients in France. Day-by-day prevalence of post COVID-19 symptoms was determined from patients’ responses to the Long COVID Symptom Tool, a validated self-reported questionnaire assessing 53 symptoms. Among patients symptomatic after 2 months, 85% still reported symptoms one year after their symptom onset. Evolution of symptoms showed a decreasing prevalence over time for 27/53 symptoms (e.g., loss of taste/smell); a stable prevalence over time for 18/53 symptoms (e.g., dyspnoea), and an increasing prevalence over time for 8/53 symptoms (e.g., paraesthesia). The disease impact on patients’ lives began increasing 6 months after onset. Our results are of importance to understand the natural history of post COVID-19 disease.

Open access, https://www.nature.com/articles/s41467-022-29513-z

 

Moved post

 

The lead author, highlighting in their own words what they think are the main points:

https://twitter.com/user/status/1512393686381961216

 

After looking through this, I'm a little doubtful. Their abstract makes it seem like they followed 968 people from 2 months to 12 months and 15% recovered, but I think they only had 146 participants who started at two months and not all of these were still in the study at 12 months (if I'm interpreting correctly, about 70 people completed the whole study from 2 to 12 months). The rest of the patients entered and left the study at various points (in fact 25% of the 968 only joined the study 300 or more days after infection) and they claim to deal with through statistics that accounts for left and right censoring. Best case, the study has a lot lower power than it appears.

But it looks like 150 of the 968 went into remission at some point in the study and then 50 of those relapsed later. So somewhere between 100-150 were in remission at the end of one year. But I'd be pretty surprised if there weren't better remission rates for those with symptoms at 2 months compared to those who had symptoms at 10 months. Can you square 10-15% in remission at 12 months out of the total cohort, when many of those entered the study at 6, 8 or 10 months, with the claim of 15% remission at 12 months for those with symptoms at 2 months?

And then looking at their conclusions about the percentage reporting unacceptable disease state changing over time, I definitely wonder if this might be due to a lot of people entering the study in the latter part of it who were more likely to report unacceptable disease state (surely, people who are finding their LC is unacceptable would be more likely to join a LC study at 6-10 months post infection than people who thought their disease state was acceptable). I think this is supposed to be accounted for in the statistics, but whether that's reasonable or not is over my head.

The reviewers noted this issue, but it seems like they were satisfied with the answers that the authors gave.

It certainly seems true that remission rates from LC are quite low, but perhaps this study's headline is less conclusive than it would appear.