Here is a link to the study
https://www.medrxiv.org/content/10.1101/2020.04.16.20065920v1
This retroactive study means nothing as there is no control over random assignment of patients who were assigned to a treatment group or non treatment group.
So the patients who were not sick enough to receive treatment had lower mortality rate.
DUH!!!
It’s like saying that cancer patients who were at advanced stages and received chemo were more likely to die.