What test to use?


I have 2 groups with n=6 each with respiratory rate taken at baseline (predose), 1, 2, 3, and 4 hour postdose. I have figures with baseline subtracted means and SD at each timepoint and need to know whether there is a difference between groups. Can it be as simple as running multiple t tests at each timepoint using the baseline subtracted values or would it be best to do a two way anova and compare against the baseline values for each group?


Not a robit
If they are randomized do you need to subtracted out baseline RR, shouldn't these values be comparable given the design?
Last edited:
Maybe I can take the baseline subtracted values for both groups and run two way rm anova (time and treatment) to compare the two groups at each timepoint...would that make sense?


Not a robit
The sample size is just so small, you are going to need a big difference especially after controlling for multiple tests (false discovery). You will also need to test assumptions for the model (e.g., linearity and residuals). I want to say conduct a corrected permutation test, but given your sample size I not even sure that may work.

P.S., It is traditional to control for the baseline value in the model, not subtract it out - but your model is lacking degrees of freedom.