[R-meta] How does rma handle effect size of zero

Divya Ravichandar d|vy@ @end|ng |rom @econdgenome@com
Mon Jun 8 21:59:28 CEST 2020

Hi all

I would like to get some understanding around how rma handles effect sizes
of 0. A test example is outlined below


case1 <- data.frame(Study= c("a","b","c","d"),ES=rep(.1,4),SE=rep(1e-5,4))
%>% rma(ES, SE^2, data=.) #non zero case
meta_case1 <- rma(ES, SE^2,  data=case1)
case2 <- data.frame(Study= c("a","b","c","d"),ES=rep(0,4),SE=rep(1e-5,4))
%>% rma(ES, SE^2, data=.) #zero case

While case 1 results in a significant p value  (<.0001), case 2 results in
a non-significant p value (1). Does a zero effect size violate any
assumptions and if not I wonder why a consistent estimate of 0 across
datasets results in a non-significant result?


*Divya Ravichandar*
Second Genome

	[[alternative HTML version deleted]]

More information about the R-sig-meta-analysis mailing list