These numbers are low, but not low enough to ignore. Earlier we decided that the quality of life hit from long COVID after a non-hospitalized acute case was 18%. If you’re a 35 year old woman, and your risk of ending up with lifelong long COVID from catching COVID is 2.8%, then catching COVID would be the same, statistically speaking, as losing (50 years * 0.18 * 0.028 * 365 days/year) = ~90 days of your life. Ouch.
We can also look at just the “worst case scenario” – catching long COVID that doesn’t go away for years AND limits daily activities a lot. This number feels a bit more like a “mortality” rate – except in this case you don’t actually die, but your life is forever altered, and you can’t hold down a job anymore or do most of the things you used to love to do.
A 35 year old woman runs about an 0.5% chance of the “worst case scenario” outcome if she gets Delta. For comparison, 0.5% is about 42x your chance of dying in a car crash in the next year.
I think the main differences are using studies with higher excess burdens and using a lower reduction factor to translate to lifelong risk. On the latter:
In the end we need to make an educated guess, even if it’s a low-confidence one, as to how often long COVID that lasts 4.5 months ends up being lifelong. Based on the SARS data, we could guess that 80% of hospitalized acute COVID patients that that have long COVID at 4.5 months end up having it for the rest of their life. Patients with milder COVID cases tend to get less physiological damage during acute infection, so it’s possible they’ll have higher recovery rates. Again taking an educated guess and going on even less data, we might expect that 50% of long COVID cases for mild acute patients at 4.5 months end up being lifelong.
Here’s another BOTEC, by Matt Bell:
I think the main differences are using studies with higher excess burdens and using a lower reduction factor to translate to lifelong risk. On the latter: