st: Repeated measures ANOVA

[antonio.bsousa@sapo.pt]

Dear statalisters
I have a problem, maybe a simple problem for the majority of you but  
complex for me.
I?m studyng the effects of a kind of ocular surgery. I have a dataset  
with 5 measurements (CH0-CH5) and two surgical techniques. The 5  
measurements are made in the same patients, so are repeated measures.
I put the data in long format and now i have a dataset with the  
variables subject(id number), ch(variable that holds the  
measurements), chnum(variable 0-5 that tells if it was ch0 or ch1....  
to ch5) tcir(the suirgical technique a 0/1 variable).
I want to know if are differences in the mean of ch from point 0 (the  
day before the surgery) to point 5 (4 weeks after the surgery), and if  
these differences are related with the surgical technique.
I  wrote
anova subject tcir ch chnum, repeated(chnum)
and receive the message "variable not in the model"
If i drop tcir everything is ok.
How can i fix this problem? What is wrong?
I read the Stata manuals, but i don?t understand very well the solution.
Can you help me please?
Thank you
Antonio Botelho de Sousa
Bombarral-Portugal

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