As a rule of thumb, scientists hide data they don't want you to see in the Appendix or Supplemental aspect of a study.
Scroll all the way down on the Lancet study and look for the Supplementary .pdf.
If you look at the Supplementary Tables, it shows that the study is completely slanted in terms of where it got its data from. That's a bit of a problem if you're looking at how HCQ therapies affect human beings in general, versus a mostly European-descended North American population. Sampling (who they pick and from where) is usually a way that people manipulate studies to get the results that they want to get, without respect for the facts.
If you look at the next page, the average patient age is 53.8 years, you're much more likely to have preexisting conditions at that age. So, that's not good…
Then, 66.9% of people were White in the study. This is a problem for several reasons. First, drugs don't affect people of different races the same. There are racial differences in biology, from disease predispositions (e.g. sicle-cell anemia) to BMI averages, and so on. So, slanting the study towards that many White people is not a good start. The other issue is that it's very possible that those 66.9% of people aren't really even White. Most of the data came from North America and there is a lot of mixing in the US, in particular. So, this division is somewhere between problematic and a crap shoot.
Now, comes the problem of sex. Women are typically more than 50% of the population (partly because the male lifespan is shorter), but they're 46.3% of the patients? That actually goes along with the study I read elsewhere about men being more affected by the virus. There are many reasons for this. But, if you go back to the Lancet page with the study, it claims: "After controlling for multiple confounding factors (age, sex, race or ethnicity…" -- How did they 'control' for these things? This is a huge problem right here, though it might not seem that way. How they 'control' for age, sex, race, ethnicity, etc., can slant the data in one direction or another. When you factor in the issue of P.C. culture being rampant in science these days, the question arises: Did they treat males/females and different races/ethnicities the same? This would be a serious problem because not only have I read studies showing that males are more affected by the virus, I've read studies that found that people of certain ethnicities (e.g. Asian descent) were more affected by the virus. Virus vulnerability can be related to cell structure, which can be genetic, which is related to ethnicity. So, treating all races/ethnicities as if they're the same would be a serious problem.