Hello metafor users, I'm using metafor to perform a single-effect summary estimate of the raw proportion of patients experiencing a post-operative complication, and I'm interested in seeing if this proportion differs between the three most commonly used surgical techniques. The software is working as expected, but I would like to double check on the interpretation of my mixed-effect model summary.
The levels of my moderator variable surgery.type are LateralWedge, Dome, and Complex, which I've dummy coded like this: dat$LateralWedge<-ifelse(dat$Technique=="LateralWedge",1,0) datDome<-ifelse(dat$Technique=="Dome",1,0) dat$Complex<-ifelse(dat$Technique=="Complex",1,0) When i fit this random effect model: rma(yi,vi,data=dat, mods=cbind(LateralWedge,Dome,Complex)) I get this output: /Mixed-Effects Model (k = 33; tau^2 estimator: REML) logLik Deviance AIC BIC -11.2426 22.4852 30.4852 36.0900 tau^2 (estimate of residual amount of heterogeneity): 0.0925 (SE = 0.0269) tau (sqrt of the estimate of residual heterogeneity): 0.3041 Test for Residual Heterogeneity: QE(df = 30) = 654.3038, p-val < .0001 *Test of Moderators (coefficient(s) 1,2,3): QM(df = 3) = 128.7528, p-val < .0001* Model Results: estimate se zval pval ci.lb ci.ub LateralWedge *0.6462* 0.0722 8.9450 <.0001 *0.5046 0.7878* *** Dome *0.6659 * 0.1471 4.5283 <.0001 *0.3777 0.9541 * *** Complex *0.6938* 0.1306 5.3136 <.0001 * 0.4379 0.9498* ***/ My suspicion is that the test of moderators is addressing the hypothesis that the proportion of my outcome is not zero in any of the three groups, because all the estimated proportions appear to be well within the confidence bounds of the other two groups. Is this correct? If it is, I would appreciate any suggestions on how I would change that hypothesis test, so that I am testing whether the proportion in group 1 = the proportion in group 2 = the proportion in group 3? Thanks for your input, Christopher Anderson -- View this message in context: http://r.789695.n4.nabble.com/metafor-interpretation-of-moderators-test-for-raw-proportions-tp4638972.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.