I am doing meta analysis using "rma" (function) in the "metafor" package (in R). And this is my first time to do meta analysis.
The estimate is a proportion (# of patients with good outcome / Total # of patients).
Each paper has two groups to compare (Treatment 1 vs Treatment 2).
However, I do also know the average age, # of females, and location (country) of each paper.
I suspect that these three covariates affect the "proportion";
therefore I would like to adjust the effect from them.
In rma function, there is an argument called "mods", where I can put "moderator" variables. In such case, to adjust covariates, can I use (something like)
rma.da.adjusted <- rma(yi, vi, data = meta.dat, method = "DL", mods = ~ age + female + location + treatment_group )
Here, age and female are continuous covariates, and location and treatment_group are categorical covariates.
Thank you in advance!!