paired t-test - differences by group

[LucyB]

I have pre/post data for one group - outcome is a score. I am interested to see if the scores vary by a covariate like gender. If I use the by command in the ttest procedure, it does not give me a significant p value for differences by gender. how can i go about doing this?

[Reeza]

I think you need a PROC ANOVA not a T-Test. 

[LucyB]

So would be outcome variable be the difference? And my independent would be gender, but do I need to adjust for baseline (pre) scores as well?

[Reeza]

Pre-calculate the differences and test if the difference is different between the groups and not equal to 0. 

ie Mean from Group A = Mean from Group B = Mean from Group  = 0

where mean = post-pre score

[Reeza]

Also, BY statements splits an analysis for each group. It's the equivalent of doing some repeatedly for each group but they're considered individually. Analyses do not cross between BY groups.