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Hi all, I plan to fit a mixed-effects meta-regression model with metafor::rma(). The moderator would be categorical (3 subgroups). If I?m not mistaken, rma() estimates a common tau^2 across subgroups. Is it possible to estimate...

Hi all, Borenstein & Higgins refer to two type of models: Within-subgroups and between-subgroups. Because there is no code, it wasn?t clear to me what they are actually referring to. Could someone clarify this topic? Within-subgroups model...

Hi all, I want to fit a network (ie, >= 3 treatments) meta-analysis with multiple (>=2) outcomes using metafor. The concepts are described in this article by Riley et al?https://www.bmj.com/content/358/bmj.j3932 I could...

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...

Hi all, I need some help to figure out how to fit a?bivariate generalized linear mixed model using metafor. In the past year, the Journal of Clinical Epidemiology has posted several articles on a controversy between using risk ratio...

I see. Thank you very much, Wolfgang. Btw, sorry for my?persistence! This subject *was* a little bit confusing until you elucidated everything. Best, Arthur M. Albuquerque Medical student Universidade Federal do Rio de Janeiro, Brazil On Mar 9, 2022...

Wow, crazy numerical coincidence then. I?ve been wondering about applying Reference [1] model (= your Model 6) in future projects. Can you see any practical reason to apply the?(group | study) syntax instead of (control+treat-1|study)? Best, Arthur...

Hi all, I have a couple of questions about using metafor::vcalc() to create a variance-covariance matrix when many effect sizes reflect the difference between two conditions and there is a shared control group. ?According to its documentation (https...

My effect size of interest is the odds ratio. A random effect logistic regression with random intercept by study won?t account for the shared control group within each study. What other alternative do I have over the sandwich estimator...

Very enlightening code, thank you!! I noted that you used a different lme4 syntax for this model in your article with Jackson et al with?a ?control? indicator and removed the intercept within the random effect. I compared both syntax...

Dear Wolfgang, Thank you in advance. I contacted Reference [1] authors, and they sent me this data: structure(list(study.name = c("Cutler1995", "Dahlof1991", "Dowson2002", "Ensink1991", "Geraud2000", "Goadsby1991", "Goadsby2000", "Havanka2000", "Kaniecki2006", "Mathew2003", "Myllyla1998", "Nappi1994", "Patten1991", "Pfaffenrath1998", "Sandrini2002", "Sargent1995", "Sheftell2005", "Tfelt...

Wolfgang, I now realized this discussion is related to the discussion presented in this book:?https://bookdown.org/MathiasHarrer/Doing_Meta_Analysis_in_R/subgroup.html To my understanding, they argue - while citing?Borenstein & Higgins 2013 - that the models you...

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...

Following your article "A comparison of seven random-effects models for meta-analyses that estimate the summary odds ratio?, would that be "Model 4: a modified version of Simmonds and Higgins model?? glmer(cbind(event,n-event)~factor(study)+factor...

Thanks a lot. On Mar 6, 2023, 6:44 PM -0300, Viechtbauer, Wolfgang (NP) <wolfgang.viechtbauer at maastrichtuniversity.nl>, wrote: > I don't remember our numbering off the top of my head, but yep, that is the model I just...

Dear Wolfgang, Thank you for the super quick reply! I wasn?t aware of that article, yet I believe it does not include the model I mentioned. The model is thoroughly described at the end of this article, section "Appendix...

Dear Wolfgang, We had this discussion back in October, so you might not remember. In brief, I wanted to fit a Bivariate model and you pointed towards the Model 6 in your excellent article: Jackson, D., Law, M., Stijnen, T...

Dear Michael, I?m sorry, my bad. It?s a binomial model with the logit link, in which the average baseline and treatment risks are treated as fixed effects. Moreover, there are two study-specific parameters (random-effects), and these...

Hi Wolfgang, It?s me again about this bivariate model. I am having a hard time trying to figure out if I understood it correctly. To recap, I wanted to fit a bivariate meta-analysis model (hereafter, mod1) described in...

Absolutely amazing, Wolfgang. Thanks! One quick question: if I were to meta-analyze log odds ratios (instead of logRRs), should I calculate the weights with output from "escalc(measure=?PLO?,?)?, instead of ?PLN? as you did? Arthur M. Albuquerque Medical...