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 deselected as a heart transplant candidate, but for the purposes of this experiment those patients were kept in the data as continuing candidates.
A data frame with 103 observations on the following 8 variables.
ID number of the patient.
Year of acceptance as a heart transplant candidate.
Age of the patient at the beginning of the study.
Survival status with levels
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
Whether or not the patient had prior surgery with levels
Transplant status with levels
control (did not
receive a transplant) and
treatment (received a transplant).
Waiting Time for Transplant
Turnbull B, Brown B, and Hu M (1974). "Survivorship of heart transplant data." Journal of the American Statistical Association, vol. 69, pp. 74-80.
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")