\title{case-control studies on the impact of alcohol consumption on breast cancer risk}
\description{results from 16 case-control studies evaluating the impact of alcohol consumption on breast cancer risk.}
\bold{year}   \tab \code{integer}   \tab publication year \cr
\bold{b}      \tab \code{numeric}   \tab adjusted log risk ratio \cr
\bold{se}     \tab \code{numeric}   \tab standard error
greenland and longecker (1992) describe a method to combine trend estimates from summarized dose-response data. a meta-analysis of 16 case-control studies evaluating the impact of alcohol consumption on breast cancer risk was used as an illustrative example. the estimates are the increase in the log relative risk of breast cancer associated with an average daily alcohol consumption of 1g.
data are provided in greenland and longecker (1992), table 3.
greenland, s., & longnecker, m. p. (1992). methods for trend estimation from summarized dose-response data, with applications to meta-analysis. \emph{american journal of epidemiology}, \bold{135}(11), 1301--1309. \verb{https://doi.org/10.1093/oxfordjournals.aje.a116237}
mg <- metagen(b, se, data = dat.greenland1992,
studlab = paste(author, year), sm = "rr",
random = false, overall.hetstat = false,
### standard error for common effect estimate

\title{studies on interventions to reduce mortality after liver transplantation}
\description{results from 14 trials examining the mortality risk of interventions for decreasing blood loss and blood transfusion requirements during liver transplantation.}
\bold{study}     \tab \code{character} \tab study information \cr
\bold{death}     \tab \code{integer}   \tab mortality at 60 days post-transplantation \cr
\bold{n}         \tab \code{integer}   \tab number of individuals
this network meta-analysis compared the effectiveness of seven interventions for decreasing blood loss and blood transfusion requirements during liver transplantation (gurusamy et al., 2011).
fourteen studies reported mortality at 60 days, in 1,002 patients. forty-five deaths were reported across all studies (4.5\%). six studies observed deaths in all treatment arms while three studies did not observe any deaths.
this dataset was used in efthimiou et al. (2019) to introduce the mantel-haenszel method for network meta-analysis.
one of the treatments (solvent detergent plasma) was only included in one study with zero events in both treatment arms; this study was excluded from all network meta-analyses. in addition, no death was observed in the antithrombin iii arm of the only study evaluating this treatment which was excluded from the mantel-haenszel network meta-analysis.
gurusamy, k. s., pissanou, t., pikhart, h., vaughan, j., burroughs, a. k., & davidson, b. r. (2011). methods to decrease blood loss and transfusion requirements for liver transplantation. \emph{cochrane database of systematic reviews}, \bold{12}, cd009052. \verb{https://doi.org/10.1002/14651858.cd009052.pub2}
### only study evaluating solvent detergent plasma
subset(dat.gurusamy2011, study == "williamson 1999")
### only study evaluating antithrombin iii
subset(dat.gurusamy2011, study == "baudo 1992")
pw <- pairwise(treatment, death, n, studlab = study,
### conduct inverse variance (iv) network meta-analysis
netgraph(net.mh, seq = "optimal", col = "black", plastic = false,
### full network graph (based on inverse variance method, including
### study comparing antithrombin iii with control/placebo)
seq = "optimal", col = "black", plastic = false,
### compare results for mantel-haenszel and iv nma
random = false, name = c("mh nma", "iv nma")))
print(netsplit(net.mh), show = "both", ci = true, overall = false,