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?
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.
Do you mean you want the ANOVA run for each group separately? If so, try using a BY statement.
What p-value would give me the significance of the difference between pre and post then?
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.
Don't know why I didn't think of that - thanks!
Don't miss out on SAS Innovate - Register now for the FREE Livestream!
Can't make it to Vegas? No problem! Watch our general sessions LIVE or on-demand starting April 17th. Hear from SAS execs, best-selling author Adam Grant, Hot Ones host Sean Evans, top tech journalist Kara Swisher, AI expert Cassie Kozyrkov, and the mind-blowing dance crew iLuminate! Plus, get access to over 20 breakout sessions.
ANOVA, or Analysis Of Variance, is used to compare the averages or means of two or more populations to better understand how they differ. Watch this tutorial for more.
Find more tutorials on the SAS Users YouTube channel.