It is a 3-treatment (A,B,C), 3-period (1, 2, 3), 2-sequence (ABC, BAC). subjects are randomized to the 2 sequences, stratified by BMI (4 levels: 1,2,3,4). I want to know whether there are response differences between BMI levels (1 vs. 4, 2 vs. 4, 3 vs. 4) within each treatment (A, B, C). I'm testing the model using dummy data. I tried 40 subjects' data, but LSM estimate for the treatment is always NON-est. Of course, result is NON-est for ESTIMATE statment. Nothing wrong in log, the data will converge. I tried more subjects (80) data, and different dummy data for RESPONSE, but always got NON-est results. Can anyone advise what could possibly go wrong here? Any suggestions will be greatly appreciated! The data structure is like- subjid sequence period trt BMI response S1 ABC 1 A 1 xx S1 ABC 2 B 1 xx S1 ABC 3 C 1 xx S2 BAC 1 B 1 xx S2 BAC 2 A 1 xx S2 BAC 3 C 1 xx .... ; proc mixed data = xx; class subjid sequence period bmi trt ; model response = sequence period bmi trt bmi*trt; random subjid(sequence); lsmeans bmi trt bmi*trt; ESTIMATE 'BMI 1 vs. 4 within TRT A' BMI 1 0 0 -1 bmi*trt 1 0 0 -1/cl; run;
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