dat.lau1992 {metadat}

Studies on Intravenous Streptokinase for Acute Myocardial Infarction

Description

Results from 33 trials comparing intravenous streptokinase versus placebo or no therapy in patients who had been hospitalized for acute myocardial infarction.

Usage

dat.lau1992

Format

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

Details

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.

Concepts

medicine, cardiology, odds ratios, cumulative meta-analysis

Author(s)

Wolfgang Viechtbauer, [e-mail], https://www.metafor-project.org

Source

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

Examples

### 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)