st: Extracting coefficients from xtmixed model

[Debs Majumdar <debs_stata@yahoo.com>]

Hello,

   I have an unbalanced data set with 6 visits and the sample size goes down from around 900 at baseline to 480 at the last visit. I wanted to extract the estimate for visit from my longitudinal data. One of my fellow colleagues asked me to use


   statsby , by(rid): regress dep_A visit,

 which give me "_b_visit" in the output. First, Is this a good way to do this? I would rahter fit a mixef effects model.



When I tried to use the same command after adding more covariates using statsby , by(rid): regress dep_A visit bvol hcv whitmathyp, I don't really get any a different result and I think because I do have missing values for the predictors.


I was thinking of the following model and extracting"_b_visit" for the participants. How does one do it in Stata?


xtmixed dep_A visit bvol hcv whitmathyp ||rid:visit, cov(uns)


Thanks,

 Debs


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