\title{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.}
\bold{ai}    \tab \code{numeric}   \tab number of deaths in the streptokinase group \cr
\bold{n1i}   \tab \code{numeric}   \tab number of patients in the streptokinase group \cr
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 \squote{examples} for code that replicates the results and shows corresponding forest plots.
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. \emph{new england journal of medicine}, \bold{327}(4), 248--254. \verb{https://doi.org/10.1056/nejm199207233270406}
### 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)
### forest plot of the cumulative results
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$k:1)[id], paste0("z = ", fmtx(sav$zval[id], digits=2),
fmtp(sav$pval[id], pname=", p", equal=true, sep=true, add0=true)))
medicine, cardiology, odds ratios, cumulative meta-analysis

\title{studies on acupoint p6 stimulation for preventing nausea}
\description{results from studies examining the effectiveness of wrist acupuncture point p6 stimulation for preventing postoperative nausea.}
\bold{id}     \tab \code{numeric}   \tab trial id number \cr
\bold{study}  \tab \code{character} \tab first author \cr
\bold{year}   \tab \code{numeric}   \tab study year \cr
\bold{ai}     \tab \code{numeric}   \tab number of patients experiencing nausea in the treatment group \cr
\bold{n1i}    \tab \code{numeric}   \tab total number of patients in treatment group \cr
\bold{ci}     \tab \code{numeric}   \tab number of patients experiencing nausea in the sham group \cr
\bold{n2i}    \tab \code{numeric}   \tab total number of patients in the sham group
postoperative nausea and vomiting are common complications following surgery and anaesthesia. as an alternative to drug therapy, acupuncture has been studied as a potential treatment in several trials. the dataset contains the results from 16 clinical trials examining the effectiveness of wrist acupuncture point p6 stimulation for preventing postoperative nausea.
lee, a., & done, m. l. (2004). stimulation of the wrist acupuncture point p6 for preventing postoperative nausea and vomiting. \emph{cochrane database of systematic reviews}, \bold{3}, cd003281. \verb{https://doi.org/10.1002/14651858.cd003281.pub2}
### meta-analysis based on log risk ratios
res <- rma(measure="rr", ai=ai, n1i=n1i, ci=ci, n2i=n2i, data=dat)