[R-meta] Sample-size weighting of estimates of response ratios?

[Viechtbauer, Wolfgang (NP)]

Dear Will,

metafor allows the user to adjust the weights to any weights deemed reasonable. See the 'weights' argument in rma.uni() and the 'W' argument in rma.mv() (in the latter case, one can specify an entire weight matrix).

Best,
Wolfgang

>-----Original Message-----
>From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces using r-project.org] On
>Behalf Of Will Hopkins via R-sig-meta-analysis
>Sent: Sunday, 16 April, 2023 3:36
>To: 'R Special Interest Group for Meta-Analysis'
>Cc: Will Hopkins
>Subject: [R-meta] Sample-size weighting of estimates of response ratios?
>
>I know that metafor allows meta-analysis of response ratios (aka factor
>effects or ratios of means), but I can't find in the metafor documentation
>whether it's possible to weight the individual study estimates with their
>effective sample size rather than the usual inverse of the square of the
>standard error.  Bakbergenuly et al. (2020) recommended this approach to
>reduce the downward bias in the meta-analyzed mean ratio and heterogeneity.
>I am not a user of metafor, but I need to be able to state whether it's
>available for a manuscript I am revising with a colleague (Dave Rowlands)
>about better approaches than standardization when meta-analyzing means.
>Wolfgang, is it already available, or if not, do you intend to implement it?
>
>We use SAS's proc mixed for metas, with the elegant method of setting the
>residual variance to unity, but I don't know how to adapt this method to
>weighting by sample size. If anyone on this list can enlighten me, that
>would also be cool, thank you.
>
>Will
>
>Bakbergenuly I, Hoaglin DC, Kulinskaya E. Estimation in meta-analyses of
>response ratios. BMC Med Res Methodol. 2020;20(1):263.
>doi:10.1186/s12874-020-01137-1