I am completing a meta-analysis on the effect of CBT on low self-esteem and I could use some help regarding the regression feature in metafor. Based on the studies that I am using for the analysis, I identified 4 potential moderators that I want to explore: - Some of the studies that I am using used RCTs to compare an intervention with a waitlist and others used the pre-score as the control in a single-group design. - Some of the groups took place in one day and others took several weeks. - There are three discernible interventions being represented - The initial level of self-esteem varies
Based on the above, I used this command to conduct a meta-analysis using standarized mean differences: MetaMod<-rma(m1i=m1, m2i=m2, sd1i=sd1, sd2i=sd2, n1i=n1, n2i=n2, mods=cbind(dur, rct, int, level),measure = "SMD") Would this be the best command to use for what I described? Also, what could I add to the command so that the forest plot shows a sub-group analysis using the 'dur' variable as a between-groups distinction? Also, with respect to the moderators, this is what was delivered: Test of Moderators (coefficient(s) 2,3,4,5): QM(df = 4) = 8.7815, p-val = 0.0668 Model Results: estimate se zval pval ci.lb ci.ub intrcpt 0.7005 0.6251 1.1207 0.2624 -0.5246 1.9256 dur 0.5364 0.2411 2.2249 0.0261 0.0639 1.0090 * rct -0.3714 0.1951 -1.9035 0.0570 -0.7537 0.0110 . int 0.0730 0.1102 0.6628 0.5075 -0.1430 0.2890 level -0.2819 0.2139 -1.3180 0.1875 -0.7010 0.1373 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 >From this, can I interpret that the variable 'dur' (duration of intervention) has a significant effect and the variable 'rct' (whether a study was an RCT or used pre-post scores) was just shy of being statistically significant? I mainly ask, because the QM-score has a p-value of 0.0668, which I thought would mean that none of the moderators would be significant. Would I be better off just listing one or two moderators instead of four? Much appreciated, Dan [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.