I want to study the effect of 2 drugs (used singly and in combination) compared to a placebo on a disease. What is the best statistical method? Kindly provide full details.
What you are looking to compare is to see if the mean outcome is improved or not by using the mean. You dont want to do this with ordinary t-tests as the tests are not independent and the probabilities would no longer be accurate (you would have a larger type 1 error).
Therefore you want to test the means jointly using for example an ANOVA test that does not suffer from the inflated type 1 error.