[R-meta] Rare dependent variable with correlation among effect sizes
Hi Wolfang, thanks for the quick reply. About 2), would you fit the model in lme4 then use a sandwich estimator? As you said, a regular random-effect model in lme4 would be analog to rma.glmm().
On Mar 6, 2023, 5:45 PM -0300, Viechtbauer, Wolfgang (NP) <wolfgang.viechtbauer at maastrichtuniversity.nl>, wrote:
Hi Arthur, Just a small correction: vcov() should be vcalc(). But to your actual question: rma.glmm() doesn't handle that. Some options: 1) use rma.mv() with a measure like "AS" and use vcalc() to construct the V matrix. 2) go straight to lme4::glmer(). Except for the non-central hypergeometric model, rma.glmm() is in essence just a wrapper for lme4::glmer() (or GLMMadaptive / glmmTMB as alternatives). Best, Wolfgang
-----Original Message----- From: R-sig-meta-analysis [mailto:r-sig-meta-analysis-bounces at r-project.org] On Behalf Of Arthur Albuquerque via R-sig-meta-analysis Sent: Monday, 06 March, 2023 21:17 To: R meta Cc: Arthur Albuquerque Subject: [R-meta] Rare dependent variable with correlation among effect sizes Hi all, Tl;dr: I want to meta-analyze studies with a rare dependent variable with correlation among effect sizes. I have four randomized controlled trials. Within each RCT, there is one ?control? group and multiple (>3) ?experimental? groups. Thus, there is a shared control group which induces correlation among the effect sizes within each RCT. I am aware that constructing a variance-covariance matrix with vcov() then fitting the model with rma.mv() is an appropriate solution (per topic 5 in ?Details? in ?vcov). Such approach requires one to first estimate effect sizes with escalc(). However, I am dealing with RCTs with a rare dependent variable. In these cases, using an exact likelihood (in this case, Binomial) is preferable. I believe rma.mv() does not support such likelihood. How can I fit such model with rma.glmm() considering?correlation among effect sizes? Ideally, I?d like to fit a random effect model. Best, Arthur