[R-meta] BLUPs revisit

[Yefeng Yang]

Hi all,

Would someone like to provide some comments on my question? I would be grateful, if could help me out, especially the MA experts like Wolfgang and James.

Best,
Yefeng

________________________________
From: R-sig-meta-analysis <r-sig-meta-analysis-bounces using r-project.org> on behalf of Yefeng Yang via R-sig-meta-analysis <r-sig-meta-analysis using r-project.org>
Sent: 26 January 2024 11:41
To: r-sig-meta-analysis using r-project.org <r-sig-meta-analysis using r-project.org>
Cc: Yefeng Yang <yefeng.yang1 using unsw.edu.au>
Subject: [R-meta] BLUPs revisit

Dear the community,

Hope you are all doing well in the new year.

I am very interested in BLUPs in meta-analysis. I have asked relevant questions before; something like whether sd of the BLUPs is equal to the tau. I got an excellent answer from the community.

Now I have a new one. I am considering whether we can use BLUPs to assess the statistical properties of the studies included in a meta-analysis. Very much appreciated in advance.

I would like to use a numerical example to present my question. Let's calculate the BLUPs with:
dat <- escalc(measure="RR", ai=tpos, bi=tneg, ci=cpos, di=cneg, data=dat.bcg)
res <- rma(yi, vi, data=dat)
study_es <- blup(res)

The value `prep` in ` blup(res)` or object `study_es ` is actually the study-specific effect, which accounts for the sampling errors.

If I use `prep` to divide by `se` (another value in ` blup(res)` or object `study_es `), I will get the so-called signal-noise-ratio (SNR), which is different from the test statistic of each effect: yi/sqrt(vi). Next, assuming there is no publication bias, I can use SNR to calculate the power for each study: Phi(-1.96 - SNR) + 1 - Phi(1.96 - SNR). The advantage of this method is that we do not need to assume the meta-analytic effect size estimate (overall mean) is the true effect for each study.  I have two specific questions:
(1) ​Does this sound reasonable? I feel something wrong with using the `se` as the standard error of the study-specific true effect - not quite sure we should use `se` or sqrt(vi),
(2) Some literature criticizes that empirical BLUPs have large uncertainty. S to properly use them, one needs to account for the uncertainty. If this is the case, how to account for it?

Best,
Yefeng





        [[alternative HTML version deleted]]

_______________________________________________
R-sig-meta-analysis mailing list @ R-sig-meta-analysis using r-project.org
To manage your subscription to this mailing list, go to:
https://stat.ethz.ch/mailman/listinfo/r-sig-meta-analysis

	[[alternative HTML version deleted]]