Appendixes | Report Option Descriptions | Model baseline as:

Model baseline as:
Use the radio buttons to specify how you want to use the baseline measurements as the standard of comparison, in a repeated-measures ANOVA model.
Your options include Covariate or Response .
When you select covariate , the first observation for each subject is removed. The deleted values are then averaged. This average value is entered as the first fixed effect and used as a covariate in the repeated-measures anova model.
When you select response , the baseline measurements are treated the same as the trial measurements in the repeated-measures anova model.
For Additional Information
Refer to SAS for Mixed Models 1 for additional details about Repeated Measures anova .

Littell, R.C., G.A. Milliken, W.W.Stroup, R.D. Wolfinger, and O. Schabenberger. 2006. SAS for Mixed Models, Second Edition Cary, NC: SAS Institute Inc..