Dear all,
I have data containing one dependent variable, I'll call it Y for simplicity, and let's assume it is normally distributed.
I have independent variables X1, X2, X3, X4. All of them are ordinal, getting values of 1-4, where 4 is highest and 1 lowest. In addition, I have some covariates, such as age, gender, etc...
I wish to model Y vs. the independent variables and the covariates, but I am mostly interested in finding if there are significant differences between groups 1 and 4 of each independent variable.
Using the following code:
PROC GLM DATA = Dat;
CLASS X1;
MODEL Y = X1 Age Gender ;
LSMEANS X1 / cl pdiff diff;
RUN;
Gives me a linear model, with multiple comparisons of all pairs of the variable X1.
Is there a better way to model in this situation ? Is there a way to define something like a contrast, so only groups 1 and 4 will be compared with higher power ? Is my code correct in the first place ?
Thank you in advance !
