# What would the best statistics method to use if looking at the treatment of 2 groups of patients?

Sorry if this is a very basic question, but I don’t have much experience with statistics.

Say I have 2 groups. Each groups have about 1000 patients each. The first group is treated by a drug in an interval of 10 years with (patients can be treated in different years independently from each other) and the second group is an untreated control group. The control group and the treated group are measured in the same exact years.

The data in both groups is a score of how well they’re doing where each patient has a score for each year (the treated patients also have scores before their treatments).

I’m thinking doing maybe a student’s t-test to find out what the correlation is between the two groups. I’m thinking an independent two-sided t-test. Do you think this would be meaningful?

I’m also thinking about using a regressional model to maybe implement the treatment years.

Could there be any other statistical methods I could use?

• For me sounds ok as long as the data follows a normal distribution. Otherwise use nonparametric statistics such as Mann–Whitney U or Wilcoxon rank sum tests. May 30, 2018 at 8:02
• I think your formulation is quite clear, but it would be clearer if you could add table showing how the data look like May 30, 2018 at 8:36
• @Jimbou: Thanks for the suggestions, I'll have a look at them. May 30, 2018 at 8:48
• @fabiob: Here is a sample of the data where each row is a patient: i.imgur.com/xocr7A6.jpg May 30, 2018 at 8:49
• thanks! do I understand your data right that patient 14 receives a treatment in 2008 (or 2009)? what about participant 10? is she receiving treatment in or before 2005? your data do not seem to be normally distributed... there are many particippants full of zeros... or are these not receiving treatment (and because of this they feel bad)? May 30, 2018 at 9:00