I am trying to model a continous variable across the time with several timepoints (0,3,6,9 and 12 months) and 2 predictors.

One is continuous (5 and 10) and the other is categorical (A, B and C) and for each of the combinaison I have 30 replicates.

The relation between Y and the time is not expeted to be linear. My main concern is to study the behavior of Y along the time and see if the 2 predictors included in the experiment have an influence.

Which statistical methodology/SAS procedure would you recommend?

Here is what I've used so far (SAS CODE):

ODS GRAPHICS ON;

**PROC**

**GLM**DATA=STUDY PLOTS=ALL;

CLASS Component;

MODEL Y = Timepoint Timepoint*Timepoint Component FillingCoefficient FillingCoefficient*Timepoint Timepoint*Component / SOLUTION;

OUTPUT OUT=STUDY_results PREDICTED=pred RESIDUAL=res COOKD=Dcook RSTUDENT=rstud;

**RUN**;

Thanks in advance.

Cédric.