Transition analysis

[chintu red]

Hi
I want to do a transitional analysis. I have the following transition periods that is
1. No morbidity to mild morbidity
2. Mild morbidity to severe morbidity
3. Mild to No morbidity
4. Severe to No Morbidity

I want to do a regression analysis for these transitions on a longitudinal data. Can anyone please suggest me some methodology for this type of data.

Thanks in advance