data-heart_transplant.R

#' Heart Transplant Data
#'
#' The Stanford University Heart Transplant Study was conducted to determine
#' whether an experimental heart transplant program increased lifespan. Each
#' patient entering the program was designated officially a heart transplant
#' candidate, meaning that he was gravely ill and would most likely benefit
#' from a new heart. Then the actual heart transplant occurs between a few
#' weeks to several months depending on the availability of a donor. Very few
#' candidates during this waiting period show improvement and get
#' \emph{deselected} as a heart transplant candidate, but for the purposes of
#' this experiment those patients were kept in the data as continuing
#' candidates.
#'
#'
#' @name heart_transplant
#' @aliases heartTr heart_transplant
#' @docType data
#' @format A data frame with 103 observations on the following 8 variables.
#' \describe{
#'   \item{id}{ID number of the patient.}
#'   \item{acceptyear}{Year of acceptance as a heart transplant candidate.}
#'   \item{age}{Age of the patient at the beginning of the study.}
#'   \item{survived}{Survival status with levels \code{alive} and \code{dead}.}
#'   \item{survtime}{Number of days patients were alive after the date they were
#'   determined to be a candidate for a heart transplant until the termination
#'   date of the study}
#'   \item{prior}{Whether or not the patient had prior surgery with levels
#'   \code{yes} and \code{no}.}
#'   \item{transplant}{Transplant status with levels \code{control} (did not
#'   receive a transplant) and \code{treatment} (received a transplant).}
#'   \item{wait}{Waiting Time for Transplant}
#'   }
#' @references Turnbull B, Brown B, and Hu M (1974). "Survivorship of heart
#' transplant data." Journal of the American Statistical Association, vol. 69,
#' pp. 74-80.
#' @source \url{http://www.stat.ucla.edu/~jsanchez/data/stanford.txt}
#' @keywords datasets heart transplant categorical data contingency tables
#' randomization tests
#' @examples
#'
#' library(ggplot2)
#'
#' ggplot(heart_transplant, aes(x = transplant, y = survtime)) +
#'   geom_boxplot() +
#'   labs(x = "Transplant", y = "Survival time (days)")
#'
#' ggplot(heart_transplant, aes(x = transplant, fill = survived)) +
#'   geom_bar(position = "fill") +
#'   labs(x = "Transplant", y = "Proportion", fill = "Outcome")
"heart_transplant"