\title{studies on ketotifen alone or as additional medication for long-term control of asthma and wheeze in children}
\description{results from 10 trials reporting the physicians' judgement on the overall efficacy of ketotifen for long-term control of asthma and wheeze in children.}
\bold{study} \tab \code{character} \tab study label \cr
\bold{ee}    \tab \code{integer}   \tab number of children with treament success (ketotifen group) \cr
\bold{ne}    \tab \code{integer}   \tab number of children (ketotifen group) \cr
\bold{ec}    \tab \code{integer}   \tab number of children with treament success (control group) \cr
\bold{nc}    \tab \code{integer}   \tab number of children (control group) \cr
\bold{blind} \tab \code{character} \tab blinding of clinicians \cr
results from 10 trials reporting the physicians' judgement on the overall efficacy of ketotifen for long-term control of asthma and wheeze in children. a prespecified subgroup analysis was conducted to evaluate whether the treatment effect is different in trials with adequate blinding compared to trials with inadequate / unclear blinding.
this data set is used as an example in schwarzer et al. (2015).
bassler d., mitra a. a. d., ducharme f. m., forster j., & schwarzer, g. (2004). ketotifen alone or as additional medication for long-term control of asthma and wheeze in children. \emph{cochrane database of systematic reviews}, \bold{1}, cd001384. \verb{https://doi.org/10.1002/14651858.cd001384.pub2}
schwarzer, g., carpenter, j. r., & rücker, g. (2015). \emph{meta-analysis with r}. cham, switzerland: springer.
### use dersimonian-laird estimator (which was the default in meta in the year 2015).
### furthermore, print meta-analysis results with two digits.
oldset <- settings.meta(method.tau = "dl", digits = 2)
### calculate experimental and control event rates
### conduct meta-analysis using the inverse variance method
mb3 <- metabin(ee, ne, ec, nc, method = "i",
data = dat.bassler2004, studlab = study)
### conduct subgroup analysis comparing trials with adequate blinding
### to trials with inadequate or unclear blinding
mb3s <- update(mb3, subgroup = blind, print.subgroup.name = false)
### conduct subgroup analysis assuming common between-study variance in subgroups
mb3s.c <- update(mb3s, tau.common = true)
risk ratios, medicine, subgroup analysis