[R-meta] Help with estimate adjustment

[Dr. Guido Schwarzer]

Massimo,

You could either conduct a subgroup analysis (if your covariate has few different values) or a meta-regression. Here is a fictitious example.

library(meta)

dat <- data.frame(n = rep(100, 6), mean = 1:6, sd = rep(1, 6), age = runif(6, 40, 60))
dat$age.c <- dat$age - mean(dat$age)
dat$agecat <- factor(dat$age > 50, levels = c(FALSE, TRUE), labels = c("<= 50 years", "> 50 years"))

m <- metamean(n, mean, sd, data = dat)
m

# Subgroup analysis
update(m, subgroup = agecat)

# Subgroup analysis assuming a common between-study variance in subgroups
update(m, subgroup = agecat, tau.common = TRUE)
metareg(m, ~ agecat) # same result

# Meta-regression using continuous covariate
metareg(m, ~ age.c)


Best,
Guido