I also am skeptical that this effect could fail to partly fade with time or as symptoms fully go away, whereas they are claiming to not see such effects.
I’m also skeptical because effects from time in ICU for other respiratory diseases and other conditions do partly fade if you wait long enough (e.g. 6-12 months). Trying to make sense of the supplementary figures, it seems to me that nearly all subjects did the cognitive test less than 3 months after the onset of Covid (despite what the figure actually shows). Here’s the figure (downloaded from this page):
The top graph suggests a non-trivial proportion completing the assessment 3 months after onset. However, this is self-report and lots of people erroneously believed they had Covid in the early days of the epidemic (when there was almost zero testing in the UK for mild cases). The bottom graph suggests that the cognitive assessment is mostly over by the end of May. So people with onset >3 months earlier had Covid before the start of March. Yet the UK had very few cases before March: the first wave peak was after April 15. On March 13, there had been a total 10 deaths (corresponding to 1000 cases on a 1% IFR). So I think their inferred “illness onset” plot on the bottom graph is seriously flawed. I haven’t run the numbers, but I’m guessing that the time from onset of Covid to assessment is (i) a narrower distribution than the top figure (due to truncating at 3 months), and (ii) has a mode shifted left of 2 months.
If I’m right in my analysis, this suggests the following: 1. The researchers were sloppy. 2. The study cannot tell us that much about Long Covid because the time since onset is too short.
I’m also skeptical because effects from time in ICU for other respiratory diseases and other conditions do partly fade if you wait long enough (e.g. 6-12 months). Trying to make sense of the supplementary figures, it seems to me that nearly all subjects did the cognitive test less than 3 months after the onset of Covid (despite what the figure actually shows). Here’s the figure (downloaded from this page):
The top graph suggests a non-trivial proportion completing the assessment 3 months after onset. However, this is self-report and lots of people erroneously believed they had Covid in the early days of the epidemic (when there was almost zero testing in the UK for mild cases). The bottom graph suggests that the cognitive assessment is mostly over by the end of May. So people with onset >3 months earlier had Covid before the start of March. Yet the UK had very few cases before March: the first wave peak was after April 15. On March 13, there had been a total 10 deaths (corresponding to 1000 cases on a 1% IFR). So I think their inferred “illness onset” plot on the bottom graph is seriously flawed. I haven’t run the numbers, but I’m guessing that the time from onset of Covid to assessment is (i) a narrower distribution than the top figure (due to truncating at 3 months), and (ii) has a mode shifted left of 2 months.
If I’m right in my analysis, this suggests the following:
1. The researchers were sloppy.
2. The study cannot tell us that much about Long Covid because the time since onset is too short.