within group p-value in proc glm

[Melk]

I am running an ANOVA (on change score controlling for pre) on some pre-post data for a 2 group randomized trial. I have 1 pre and 1 post measurement. I want a p-value for the within group change from pre to post for each group, separately. Any way I can output this in my GLM model?

[Reeza]

Do you mean you want the ANOVA run for each group separately? If so, try using a BY statement.

[Melk]

What p-value would give me the significance of the difference between pre and post then?

[sld · Accepted solution]

If your response variable is the difference = (pre - post) such that you have a model statement that looks something like

class group;
model difference = group;
lsmeans group / cl;

then could you test whether the estimate of each group mean is different from zero? You could even put a confidence interval around the estimate.

[Melk]

Don't know why I didn't think of that - thanks!