05-10-2016 06:24 AM - edited 05-10-2016 05:21 PM
I have an GLM and a treament variable given to the patient in a factorial fashion coded in the following manner
2-oral drug A
4-drug A and B togther
My outcome variable is the weekly number of puffs of albuterol taken for the patient's asthma.
I need to test whether the treatment effect, which is significant in my model, can be attributed entirely to the inhaler B. Can someone help me in how I might test this in SAS? Would it be some sort of contrast statement? Thanks all.
05-13-2016 08:30 AM
Unfortunately, this experimental design isn't really a factorial, as each patient proceeds through the four treatments in the same order.
In that sense, this is a repeated measures design, with a response variable that is a count. In order to get the comparisons you want, you'll likely want to use PROC GLIMMIX.
Try the following for a comparison of the marginal estimates:
proc glimmix data=yourdata; class ID treatment; model count = treatment / dist=poisson; random treatment / residual type=un subject=ID; lsmeans treatment / diff; run;
This should at least get you started. There may be some glitches along the way as far as convergence, etc., but those can be dealt with.