I am working with medical data and specifically determining whether Treatment_X is safe in certain prognostic groups of patients with chronic liver disease.
To summarize: a common prognostic score for liver disease patients is the Child Pugh Score, which takes on integer score 5-15, and is classified into categories A, B, and C depending on the numeric score (A, 5-6; B, 7-9; C 10-15). Please note that lower is better
We are interested in the change in numeric CP Score from pre-treatment to post-treatment after treatment with Treatment_X.
If we define a clinically meaningful increase in CP score as 2, we are interested in testing whether the rate of clinically meaningful increase in CP score is greater among patients who are "Child Pugh B" category before treatment compared to those who are in the more favorable "Child Pugh A" category.
What would be the best statistical method to analyze this data? Thank you so much for your help.