[tmdg]

This is clearly stated in the article:

"You can see that these were indeed at-risk patients – the overall mortality rate in the general population for coronavirus infections is nowhere near those rates, and it’s a damn good thing it isn’t. The mean age of the patients was 59 years, 64% male, with 50% of them having hypertension, 45% of them obese, and 30% with Type 2 diabetes. So even though they were characterized as mild-to-moderate on enrollment, this was just the sort of group that you’d worry about as a physician."

It is still a valuable study even if it is not a study done on the general population.