I am using the metafor package to assess publication bias for a meta-analysis (included approx 100 and approx 900 individual effect sizes). I am facing an issue with the implementation of the trim and fill procedure:
I have produced the funnel plot, which visually provides indication for some missing studies on the left side.
I have then conducted the Egger's test and find a significant p-value, thus confirming plot asymmetrie.
Then I have run the trim and fill procedure (using the trimfill command of the metafor package), but oddly, no missing studies are identified and the pooled effect size estimate thus remains identical after having implemented the trim and fill procedure.
Does anyone know why this could be the case? Could the large sample be an issue?