As far as I can tell there was no comparison group. They checked the medical records of a bunch of people who came to the hospital with COVID infections, then c

As far as I can tell there was no comparison group. They checked the medical records of a bunch of people who came to the hospital with COVID infections, then checked how many of those developed Type 2 diabetes. Would be interesting to see how many people who didn't have COVID had increased risk of developing Type 2 diabetes. With everybody staying at home and changing behavior/eating patterns, I wouldn't be surprised if the effect size was similar there.