\title{studies on the effectiveness of injected cholera vaccines}
\description{results from 17 studies on the effectiveness of injected vaccines against cholera.}
\bold{study}   \tab \code{character} \tab author/study name and publication year \cr
\bold{ai}      \tab \code{numeric}   \tab number of cholera cases in the vaccinated group \cr
\bold{n1i}     \tab \code{numeric}   \tab number of individuals in the vaccinated group \cr
\bold{ci}      \tab \code{numeric}   \tab number of cholera cases in the placebo group \cr
\bold{n2i}     \tab \code{numeric}   \tab number of individuals in the placebo group
cholera is an infection caused by certain strains of the bacterium \emph{vibrio cholerae}. when untreated, mortality rates can be as high as 50-60\%. proper sanitation practices are usually effective in preventing outbreaks, but a number of oral and injectable vaccines have also been developed. the cochrane review by graves et al. (2010) examined the effectiveness of injectable vaccines for preventing cholera cases and death. the present dataset includes results from 17 studies that reported the number of cholera cases in vaccinated and placebo/comparison groups up to 7 months after the treatment.
graves, p. m., deeks, j. j., demicheli, v., & jefferson, t. (2010). vaccines for preventing cholera: killed whole cell or other subunit vaccines (injected). \emph{cochrane database of systematic reviews}, \bold{8}, cd000974. \verb{https://doi.org/10.1002/14651858.cd000974.pub2}
### analysis using the mantel-haenszel method
rma.mh(measure="rr", ai=ai, n1i=n1i, ci=ci, n2i=n2i, data=dat, digits=2)
medicine, risk ratios, mantel-haenszel method

\title{trials on high-dose chemotherapy with autologous stem cell transplantation in aggressive non-hodgkin lymphoma}
\description{results on complete response from 14 trials evaluating high-dose chemotherapy with autologous stem cell transplantation in patients with aggressive non-hodgkin lymphoma.}
\bold{ee}    \tab \code{integer}   \tab complete responses (high-dose chemotherapy) \cr
\bold{ne}    \tab \code{integer}   \tab number of patients (high-dose chemotherapy) \cr
\bold{ec}    \tab \code{integer}   \tab complete responses (standard chemotherapy) \cr
\bold{nc}    \tab \code{integer}   \tab number of patients (standard chemotherapy)
greb et al. (2008) conducted a cochrane review to assess the effects of high-dose chemotherapy with autologous stem cell transplantation as part of the first-line treatment of adult patients with aggressive non-hodgkin lymphoma. the primary outcome was survival time; the binary outcome \squote{complete response} was one of several secondary outcomes. for binary outcomes, the cochrane review used the risk ratio and the common effect model.
greb, a., bohlius, j., schiefer, d., schwarzer, g., schulz, h., & engert, a. (2008). high-dose chemotherapy with autologous stem cell transplantation in the first line treatment of aggressive non-hodgkin lymphoma (nhl) in adults. \emph{cochrane database of systematic reviews}, \bold{1}, cd004024. \verb{https://doi.org/10.1002/14651858.cd004024.pub2}
### conduct common effect meta-analysis with risk ratio as effect measure
label.e = "high dose", label.c = "standard",
label.left = "favours standard chemotherapy",
label.right = "favours high dose chemotherapy",
col.label.left = "red", col.label.right = "green")