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plots:forest_plot_with_subgroups [2021/03/29 19:47] – Wolfgang Viechtbauerplots:forest_plot_with_subgroups [2021/05/16 16:06] – Wolfgang Viechtbauer
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 ### fit random-effects model ### fit random-effects model
 res <- rma(yi, vi, data=dat) res <- rma(yi, vi, data=dat)
 +
 +### a little helper function to add Q-test, I^2, and tau^2 estimate info
 +mlabfun <- function(text, res) {
 +   list(bquote(paste(.(text),
 +      " (Q = ", .(formatC(res$QE, digits=2, format="f")),
 +      ", df = ", .(res$k - res$p),
 +      ", p ", .(metafor:::.pval(res$QEp, digits=2, showeq=TRUE, sep=" ")), "; ",
 +      I^2, " = ", .(formatC(res$I2, digits=1, format="f")), "%, ",
 +      tau^2, " = ", .(formatC(res$tau2, digits=2, format="f")), ")")))}
  
 ### set up forest plot (with 2x2 table counts added; the 'rows' argument is ### set up forest plot (with 2x2 table counts added; the 'rows' argument is
 ### used to specify in which rows the outcomes will be plotted) ### used to specify in which rows the outcomes will be plotted)
-forest(res, xlim=c(-16, 6), at=log(c(0.05, 0.25, 1, 4)), atransf=exp,+forest(res, xlim=c(-16, 4.6), at=log(c(0.05, 0.25, 1, 4)), atransf=exp,
        ilab=cbind(dat$tpos, dat$tneg, dat$cpos, dat$cneg),        ilab=cbind(dat$tpos, dat$tneg, dat$cpos, dat$cneg),
        ilab.xpos=c(-9.5,-8,-6,-4.5), cex=0.75, ylim=c(-1, 27),        ilab.xpos=c(-9.5,-8,-6,-4.5), cex=0.75, ylim=c(-1, 27),
        order=dat$alloc, rows=c(3:4,9:15,20:23),        order=dat$alloc, rows=c(3:4,9:15,20:23),
-       xlab="Risk Ratio", mlab="", psize=1, header="Author(s) and Year")+       mlab=mlabfun("RE Model for All Studies", res), 
 +       psize=1, header="Author(s) and Year")
  
-### add text with Q-value, dfs, p-value, and I^2 statistic +### set font expansion factor (as in forest() above) and use a bold font 
-text(-16, -1, pos=4, cex=0.75, bquote(paste("RE Model for All Studies (Q = ", +op <- par(cex=0.75, font=2)
-     .(formatC(res$QE, digits=2, format="f")), ", df = ", .(res$k - res$p), +
-     ", p = ", .(formatC(res$QEp, digits=2, format="f")), "; ", I^2, " = ", +
-     .(formatC(res$I2, digits=1, format="f")), "%)")))+
  
-### fit meta-regression model to test for subgroup differences +### add additional column headings to the plot 
-res <- rma(yi, vi, mods = ~ alloc, data=dat)+text(c(-9.5,-8,-6,-4.5), 26, c("TB+", "TB-", "TB+", "TB-")) 
 +text(c(-8.75,-5.25),     27, c("Vaccinated", "Control"))
  
-### add text for the test of subgroup differences +### switch to bold italic font 
-text(-16, -1.8, pos=4, cex=0.75, bquote(paste("Test for Subgroup Differences: ", +par(font=4)
-     Q[M], " = ", .(formatC(res$QM, digits=2, format="f")), ", df = ", .(res$p - 1), +
-     ", p = ", .(formatC(res$QMp, digits=2, format="f"))))) +
- +
-### set font expansion factor (as in forest() above) and use bold italic +
-### font and save original settings in object 'op' +
-op <- par(cex=0.75, font=4)+
  
 ### add text for the subgroups ### add text for the subgroups
Line 55: Line 57:
                                "Random Allocation",                                "Random Allocation",
                                "Alternate Allocation"))                                "Alternate Allocation"))
- 
-### switch to bold font 
-par(font=2) 
- 
-### add column headings to the plot 
-text(c(-9.5,-8,-6,-4.5), 26, c("TB+", "TB-", "TB+", "TB-")) 
-text(c(-8.75,-5.25),     27, c("Vaccinated", "Control")) 
  
 ### set par back to the original settings ### set par back to the original settings
Line 68: Line 63:
 ### fit random-effects model in the three subgroups ### fit random-effects model in the three subgroups
 res.s <- rma(yi, vi, subset=(alloc=="systematic"), data=dat) res.s <- rma(yi, vi, subset=(alloc=="systematic"), data=dat)
-res.r <- rma(yi, vi, subset=(alloc=="random"), data=dat) +res.r <- rma(yi, vi, subset=(alloc=="random"),     data=dat) 
-res.a <- rma(yi, vi, subset=(alloc=="alternate"), data=dat)+res.a <- rma(yi, vi, subset=(alloc=="alternate"),  data=dat)
  
 ### add summary polygons for the three subgroups ### add summary polygons for the three subgroups
-addpoly(res.s, row=18.5, cex=0.75, atransf=exp, mlab="") +addpoly(res.s, row=18.5, cex=0.75, atransf=exp, mlab=mlabfun("RE Model for Subgroup", res.s)) 
-addpoly(res.r, row= 7.5, cex=0.75, atransf=exp, mlab="") +addpoly(res.r, row= 7.5, cex=0.75, atransf=exp, mlab=mlabfun("RE Model for Subgroup", res.r)) 
-addpoly(res.a, row= 1.5, cex=0.75, atransf=exp, mlab="")+addpoly(res.a, row= 1.5, cex=0.75, atransf=exp, mlab=mlabfun("RE Model for Subgroup", res.a))
  
-### add text with Q-value, dfs, p-value, and I^2 statistic for subgroups +### fit meta-regression model to test for subgroup differences 
-text(-16, 18.5, pos=4, cex=0.75, bquote(paste("RE Model for Subgroup (Q = ", +res <- rma(yi, vi, mods = ~ alloc, data=dat) 
-     .(formatC(res.s$QE, digits=2, format="f")), ", df = ", .(res.s$k - res.s$p), + 
-     ", p = ", .(formatC(res.s$QEp, digits=2, format="f")), "; ", I^2, " = ", +### add text for the test of subgroup differences 
-     .(formatC(res.s$I2, digits=1, format="f")), "%)"))) +text(-16, -1.8, pos=4, cex=0.75, bquote(paste("Test for Subgroup Differences: ", 
-text(-16, 7.5, pos=4, cex=0.75, bquote(paste("RE Model for Subgroup (Q = ", +     Q[M], " = ", .(formatC(res$QM, digits=2, format="f")), ", df = ", .(res$p - 1), 
-     .(formatC(res.r$QE, digits=2, format="f")), ", df = ", .(res.r$k - res.r$p), +     ", p = ", .(formatC(res$QMp, digits=2, format="f")))))
-     ", p = ", .(formatC(res.r$QEp, digits=2, format="f")), "; ", I^2, " = ", +
-     .(formatC(res.r$I2, digits=1, format="f")), "%)"))) +
-text(-16, 1.5, pos=4, cex=0.75, bquote(paste("RE Model for Subgroup (Q = ", +
-     .(formatC(res.a$QE, digits=2, format="f")), ", df = ", .(res.a$k - res.a$p), +
-     ", p = ", .(formatC(res.a$QEp, digits=2, format="f")), "; ", I^2, " = ", +
-     .(formatC(res.a$I2, digits=1, format="f")), "%)")))+
 </code> </code>
  
plots/forest_plot_with_subgroups.txt · Last modified: 2023/09/21 19:09 by Wolfgang Viechtbauer