[R-meta] conversion of OR to tetrachoric corr and its var

Hi Eran,

See:

https://wviechtb.github.io/metafor/reference/conv.delta.html

and especially the example at the very end, which directly covers your
question. Briefly, after conv.wald(), you use conv.delta() to convert the
log odds ratio and its sampling variance to the tetrachoric correlation
with its sampling variance.

Best,
Wolfgang

-----Original Message-----
From: R-sig-meta-analysis <r-sig-meta-analysis-bounces at r-project.org>

On Behalf

Of Eran Barzilai via R-sig-meta-analysis
Sent: Friday, March 15, 2024 16:05
To: r-sig-meta-analysis at r-project.org
Cc: Eran Barzilai <barze445 at newschool.edu>
Subject: [R-meta] conversion of OR to tetrachoric corr and its var

Hello,
Thank you for this great resource!

I am working on a meta-analysis in clinical psychology where I compare if
different types of childhood adverse experiences have different
associations with later in life psychopathology.
To do that I combine effect size that comes from Pearson?s r correlation,
(log) odd-ratios, and mean differences (Cohen?s D). Since all the

measures

are clinical, I assume all are continuous variables regardless of if they
were artificially dichotomized or not.

My question is mostly about conversions of OR to the tetrachoric
correlation.

Most of the studies report the 2X2 table, allowing me to calculate the
tetrachoric correlation directly using metafor?s escalc() function.
However, some only report the OR and its CI. For these studies use
metafor?sconv.wald() to calculate the log odd-ratios and their sampling
variance. Then I can metafor?s transf.lnortortet.pearson() to convert the
log odd-ratios to tetrachoric correlation.

However, does it make sense to also use this function directly on the
log-odds variance to convert it to the variance of the tetrachoric
correlation?

Alternatively, I thought of converting the log odd-ratios I calculate

from

conv.wald() to d, and then to the biserial correlations. Will this method
produce more reliable estimation of the effect-size and its variance?

Thank you for your help,
Eran

--
Eran Barzilai, Ph.D., New School for Social Research
Clinical Psychologist Postdoc, Williamsburg Therapy Group
https://williamsburgtherapygroup.com/
Part-time Faculty, The New School, Schools of Public Engagement,

Bachelor's

Program for Adults and Transfer Students
Pronouns: he, him, his