pbc {survival}R Documentation

Mayo Clinic Primary Biliary Cholangitis Data


Primary biliary cholangitis is an autoimmune disease leading to destruction of the small bile ducts in the liver. Progression is slow but inexhortable, eventually leading to cirrhosis and liver decompensation. The condition has been recognised since at least 1851 and was named "primary biliary cirrhosis" in 1949. Because cirrhosis is a feature only of advanced disease, a change of its name to "primary biliary cholangitis" was proposed by patient advocacy groups in 2014.

This data is from the Mayo Clinic trial in PBC conducted between 1974 and 1984. A total of 424 PBC patients, referred to Mayo Clinic during that ten-year interval, met eligibility criteria for the randomized placebo controlled trial of the drug D-penicillamine. The first 312 cases in the data set participated in the randomized trial and contain largely complete data. The additional 112 cases did not participate in the clinical trial, but consented to have basic measurements recorded and to be followed for survival. Six of those cases were lost to follow-up shortly after diagnosis, so the data here are on an additional 106 cases as well as the 312 randomized participants.

A nearly identical data set found in appendix D of Fleming and Harrington; this version has fewer missing values.


data(pbc, package="survival")


age: in years
albumin: serum albumin (g/dl)
alk.phos: alkaline phosphotase (U/liter)
ascites: presence of ascites
ast: aspartate aminotransferase, once called SGOT (U/ml)
bili: serum bilirunbin (mg/dl)
chol: serum cholesterol (mg/dl)
copper: urine copper (ug/day)
edema: 0 no edema, 0.5 untreated or successfully treated
1 edema despite diuretic therapy
hepato: presence of hepatomegaly or enlarged liver
id: case number
platelet: platelet count
protime: standardised blood clotting time
sex: m/f
spiders: blood vessel malformations in the skin
stage: histologic stage of disease (needs biopsy)
status: status at endpoint, 0/1/2 for censored, transplant, dead
time: number of days between registration and the earlier of death,
transplantion, or study analysis in July, 1986
trt: 1/2/NA for D-penicillmain, placebo, not randomised
trig: triglycerides (mg/dl)


T Therneau and P Grambsch (2000), Modeling Survival Data: Extending the Cox Model, Springer-Verlag, New York. ISBN: 0-387-98784-3.

See Also


[Package survival version 3.6-4 Index]