One sided meta analysis

[James Conlan]

I have extracted this data from studies of either treatment (group) 1 or 2.
I want to run a meta-analysis comparing the means, but obviously each study only has one patient group.
Am I best running a separate meta-analysis for each group, or is there a way to compare them within Stata?
Thanks

[Marcos Almeida]

If you have different treatment-groups in the studies, you may think about using network meta-analysis.