Something to think about
- obesity level
- severity of poverty
- exposure level to pollution
- diet or % with coronary and respiratory health conditions
- mental health
- racial inequalities
there should be more study on these factors. It will help to target support and response in future disease control as well as manage long term health care plans.
Off the top of my head, I'd add populaton density to that list. It obviously affects the chance of being infected, but it might also affect the risk of death by affecting the number of exposures and the initial viral load of the infection.
There are a lot of possible factors and many overlap. For example, population density and air pollution.