1. Run the PROC LOGISTIC code below and to produce output for a multinomial logistic regression model. The model can be used to describe characteristics of people with different chronic diseases using Circulatory disease (ref='2') as the reference group. Interpret the odds ratios for age, sex, and newly_diagnosed?

2. Run a model using Respiratory as the reference group and interpret the odds ratios for newly_diagnosed.

3. What information was gained by changing the reference group? That is, what do we know from the results of the new model that we did not know from the previous model?