openintro (version 2.4.0)

heart_transplant: Heart Transplant Data

Description

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.

Usage

heart_transplant

Format

A data frame with 103 observations on the following 8 variables.

id

ID number of the patient.

acceptyear

Year of acceptance as a heart transplant candidate.

age

Age of the patient at the beginning of the study.

survived

Survival status with levels alive and dead.

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

prior

Whether or not the patient had prior surgery with levels yes and no.

transplant

Transplant status with levels control (did not receive a transplant) and treatment (received a transplant).

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.

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")