Earlier quoted context omitted.
> (1) A COVID-19 infection can have long-term effects even in young people. What is the rate of this?
https://www.medrxiv.org/content/10.1101/2020.10.14.20212555v...
That said, it's notable that:
* They don't have a control group (makes it impossible to know what the baseline rate of these symptoms is in the population).
* They don't measure the various criteria for "organ impairment" before the participants caught covid (makes it impossible to know if the people who were found to be abnormal were abnormal before catching the virus -- there are a fair number of smokers and obese people in this sample, so this isn't an idle concern).
* They find a fairly strong association with hospitalization (i.e. the people who are sickest, end up having the most lingering symptoms).
* The people who were sickest tended to have the most pre-existing risk factors for the same outcomes being measured by the study (i.e. there's a hidden correlate).
Because of these limitations, you can't really draw any broad conclusions from this study. In general, I'd say that it shows that older / obese / unhealthy people are more likely to have both severe Covid, as well as concomitant symptoms of severe Covid.