I am attempting to test for a significant pattern in a reduction of prescribing drug A and an increase in the prescription of Drug B.
I have proportions of patients started on drug A vs. drug B vs. neither for many consecutive years. Time is my independent variable and the proportion is my dependent variable. Is there a way to test for statistical significance?
Example of my data:
1996: 0.4 drug A, 0.3 drug B, 0.3 none
1997: 0.3 drug A, 0.4 drug B, 0.3 none
1998: 0.2 drug A, 0.6 drug B, 0.2 none
1999: 0.1 drug A, 0.8 drug B, 0.1 none