\title{studies on pharmacologic treatments for chronic obstructive pulmonary disease}
\description{results from 39 trials examining pharmacologic treatments for chronic obstructive pulmonary disease (copd).}
\bold{study}     \tab \code{character} \tab study label \cr
\bold{year}      \tab \code{numeric}   \tab year of publication \cr
\bold{id}        \tab \code{numeric}   \tab study id \cr
\bold{treatment} \tab \code{character} \tab treatment \cr
\bold{exac}      \tab \code{numeric}   \tab number of individuals with one or more copd exacerbations \cr
\bold{total}     \tab \code{numeric}   \tab number of individuals
this dataset comes from a systematic review of randomized controlled trials on pharmacologic treatments for chronic obstructive pulmonary disease (copd) (baker et al., 2009).
the primary outcome, occurrence of one or more episodes of copd exacerbation, is binary (yes / no). for this outcome, five drug treatments (fluticasone, budesonide, salmeterol, formoterol, tiotropium) and two combinations (fluticasone + salmeterol, budesonide + formoterol) were compared to placebo. the authors considered the two combinations as separate treatments instead of evaluating the individual components.
baker, w. l., baker, e. l., & coleman, c. i. (2009). pharmacologic treatments for chronic obstructive pulmonary disease: a mixed-treatment comparison meta-analysis. \emph{pharmacotherapy: the journal of human pharmacology and drug therapy}, \bold{29}(8), 891--905. \verb{https://doi.org/10.1592/phco.29.8.891}
### print odds ratios and confidence limits with two digits
### transform data from long arm-based format to contrast-based
### format. argument 'sm' has to be used for odds ratio as summary
### measure; by default the risk ratio is used in the metabin function
pw <- pairwise(treatment, exac, total, studlab = paste(study, year),
### conduct random effects network meta-analysis (nma)
net <- netmeta(pw, common = false, ref = "plac")
netgraph(net, seq = "optimal", start = "prcomp",
labels = gsub("+", " +\n", trts, fixed = true),
plastic = true, thickness = "se.fixed", number = true,
points = true, cex.points = 5, col.points = "red",
### print and plot results for network meta-analysis
### conduct component network meta-analysis (cnma)
### compare results of nma and additive cnma
nb <- netbind(net, cnet, name = c("standard nma", "additive cnma"))
medicine, pulmonology, odds ratios, network meta-analysis, component network meta-analysis