Why are confidence intervals generated by metafor (rma.mv function) wider than in Comprehensive Meta Analysis (CMA) software? I have been asked to compare my meta-analytic results obtained from the CMA software to the results from metafor. I find that the width of my confidence intervals are larger with metafor than with CMA, and I would like to better understand the driving cause of this.
My code is as follows:
mod.model <- rma.mv(yi = r_Z,
V = v_Z,
slab = Study,
data = FullCSIData,
random = ~ 1 | Study/es.id,
test = "t",
method = "REML",
mods = ~ Measure)

CMA cannot fit such a multilevel model. This model accounts for dependence in the underlying true r-to-z transformed correlation coefficients (I assume this is what you are analyzing based on the name of the r_Z variable). If that dependence is strong, then this will tend to lead to wider CIs, since the 'effective number of estimates' is actually lower than the number of correlation coefficients you have.
