I am doing a 3-level meta-analysis using
I found a thread about bias diagnostics with an advice to use "regression test for funnel plot asymmetry". I have two questions:
- My outcome variable is log odds ratio. Which moderator should I use: sample size, or sampling variances, or inverse of sampling variances?
- Нow to interpret the results of these regressions? Do they show the presence/absence of the bias, or do they correct bias?
I tried two different moderators and got totally different results:
model with sample size as moderator -- slight change in mean effect size; test of moderators non signif.
rma.mv(yi, V, random = list(~1 | ID_2, ~1 | ID_1), mods = ~ sample_size, data=data)
model with sampling variance - huge change in mean effect size; test of moderators highly signif.
rma.mv(yi, V, random = list(~1 | ID_2, ~1 | ID_1), mods = ~ V^2, data=data)