dat.lau1992 | R Documentation |
Results from 33 trials comparing intravenous streptokinase versus placebo or no therapy in patients who had been hospitalized for acute myocardial infarction.
dat.lau1992
The data frame contains the following columns:
trial | character | trial name |
year | numeric | publication year |
ai | numeric | number of deaths in the streptokinase group |
n1i | numeric | number of patients in the streptokinase group |
ci | numeric | number of deaths in the control group |
n2i | numeric | number of patients in the control group |
In the paper by Lau et al. (1992), the data are used to illustrate the idea of a cumulative meta-analysis, where the results are updated as each trial is added to the dataset. See ‘Examples’ for code that replicates the results and shows corresponding forest plots.
medicine, cardiology, odds ratios, cumulative meta-analysis
Wolfgang Viechtbauer, wvb@metafor-project.org, https://www.metafor-project.org
Lau, J., Antman, E. M., Jimenez-Silva, J., Kupelnick, B., Mosteller, F., & Chalmers, T. C. (1992). Cumulative meta-analysis of therapeutic trials for myocardial infarction. New England Journal of Medicine, 327(4), 248–254. https://doi.org/10.1056/NEJM199207233270406
### copy data into 'dat' and examine data dat <- dat.lau1992 dat ## Not run: ### load metafor package library(metafor) ### meta-analysis of log odds ratios using the MH method res <- rma.mh(measure="OR", ai=ai, n1i=n1i, ci=ci, n2i=n2i, data=dat, slab=trial) print(res, digits=2) ### forest plot forest(res, xlim=c(-10,9), atransf=exp, at=log(c(.01, 0.1, 1, 10, 100)), header=TRUE, top=2, ilab=dat$year, ilab.xpos=-6) text(-6, 35, "Year", font=2) ### cumulative meta-analysis sav <- cumul(res) ### forest plot of the cumulative results forest(sav, xlim=c(-5,4), atransf=exp, at=log(c(0.1, 0.5, 1, 2, 10)), header=TRUE, top=2, ilab=dat$year, ilab.xpos=-3) text(-3, 35, "Year", font=2) id <- c(4, 8, 15, 33) # rows for which the z/p-values should be shown (as in Lau et al., 1992) text(1.1, (res$k:1)[id], paste0("z = ", formatC(sav$zval[id], format="f", digits=2), ", p = ", formatC(sav$pval[id], format="f", digits=4))) ## End(Not run)
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