Hi there,

I have created two piecewise graphs from linear mixed effects models. I now want to overlay them onto one graph.

Outcome is A1C.
Unit of measurement is months (pre = -12 to 0 months; post = 0 to 12 months).
Exposure is group (group==0 is the control group; group==1 is the intervention group). Study subjects only received the intervention at "post" (i.e. 0-12 months).

I get the following marginsplot graphs from the following code:

mixed a1c c.pre c.post i.group c.post#i.group if group==0 || id: , cov(unstr) reml
margins, at(pre=-12 post=0) at(pre=0 post=0) at(pre=12 post=12) vsquish
marginsplot, recast(line) ciopt(color(%20)) recastci(rarea)
Array


mixed a1c c.pre c.post i.group c.post#i.group if group==1 || id: , cov(unstr) reml
margins, at(pre=-12 post=0) at(pre=0 post=0) at(pre=12 post=12) vsquish
marginsplot, recast(line) ciopt(color(%20)) recastci(rarea)
Array



I want to combine the two graphs, so I used the following code:

mixed a1c c.pre c.post i.group c.post#i.group if group==0 || id: , cov(unstr) reml
margins, at(pre=-12 post=0) at(pre=0 post=0) at(pre=12 post=12) saving(file1, replace) vsquish

mixed a1c c.pre c.post i.group c.post#i.group if group==1 || id: , cov(unstr) reml
margins, at(pre=-12 post=0) at(pre=0 post=0) at(pre=12 post=12) saving(file2, replace) vsquish

combomarginsplot file1 file2, labels("Control" "Intervention")

Unfortunately, I get a graph that looks like this:
Array



How do I tell combomarginsplot that I want to plot the outcome against the original x-variable, rather than (File 1 vs. File 2)?

Thanks in advance!

Joseph Leung
Clinician Investigator Program PGY-7
University of British Columbia