Array Hi,

The below result shows my logistic regression, which I used to find potential confounders.
1. "Region" is my exposure, but one of its levels is not significant. What should I do in this case?
2. Also, I want to investigate how the effect of my exposure changes over the years. So, I got the year as a continuous variable. Do I need to check the linearity assumption for that?
3. For checking "year" as a confounder do I need to find "delta beta" for each level of my exposure?
4. Is it correct that the constant is not significant?

My code:
logit time i.region year i.stage i.screen
Result: Attached