st: How to plot the mean trajectory and 95%CI band afte mi estimate: xtmixed

[Khady Brumblay <kndaobr@me.com>]

Hi all,
I am trying to predict the average trajectories of a health outcome (health) overtime (year since an event). My predictors include the variables year (centered), year squared, as well as demographic (race, age, sex) and health characteristics (self-rated health, comorbid conditions). The data was imputed for item missing, using the stata mi command, which resulted in 5 datasets in addition to the original dataset. The data is currently in wide format, meaning each observation for each given year has one entry.

I have been unsuccessfully trying the plot the mean trajectory and 95%CI band after using [mi estimate: xtmixed]. I have tried different things, but none seem to work.
1) the twoway approach proposed by Rabe-Hesketh and Skrondal (p220) does not apply to imputed data using mi, and does not include time squared, interactions at different levels of data, or time varying-covariates.
2) the margin option suggested in the statalist does not work with [mi estimate] 
3) HLM does this fairly simply, and I am not sure why stata does not
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