*Continuous variables with a random-effects model (Hedges) 
*Calculate SMD: 
metan expn expmean expsd cotrn cotrmean cotrsd, label(namevar=study) xlabel(-8,-4,4,8) random hedges 


*Calculate WMD: 
metan expn expmean expsd cotrn cotrmean cotrsd, label(namevar=study) xlabel(-20,-10,10,20) nostandard

*Sensitivity analysis:
metaninf expn expmean expsd cotrn cotrmean cotrsd, label(namevar=study) random hedges

*Subgroup analysis:
metan expn expmean expsd cotrn cotrmean cotrsd, label(namevar=study) xlabel(-8,-4,4,8) random hedges by(group)