>The combination of hydroxychloroquine + azithromycin was reserved for selected patients with severe COVID-19 and with minimal cardiac risk factors.
This group still saw improvement over no treatment, which is a huge plus(unless cardiac function is correlated with covid susceptibility).
Chronic heart disease is a factor associated with higher risk of COVID-19-related hospital death, https://www.medrxiv.org/content/10.1101/2020.05.06.20092999v... gives a hazard ratio of 1.27 adjusted for all the many other factors they looked at.
So yes, it looks to me like at least some of what this Ford study measured was indeed that difference between people with pre-existing conditions dying at a higher rate than people without.
>The combination of hydroxychloroquine + azithromycin was reserved for selected patients with severe COVID-19 and with minimal cardiac risk factors.
This group still saw improvement over no treatment, which is a huge plus(unless cardiac function is correlated with covid susceptibility).