PBC {compound.Cox} | R Documentation |
Primary biliary cirrhosis (PBC) of the liver data
Description
A subset of primary biliary cirrhosis (PBC) of the liver data in the book "Counting Process & Survival Analysis" by Fleming & Harrington (1991). This subset is used in Tibshirani (1997).
Usage
data(PBC)
Format
A data frame with 276 observations on the following 19 variables.
T
Survival times (either time to death or censoring) in days
d
Censoring indicator, 1=death, 0=censoring
trt
Treatment indicator, 1=treatment by D-penicillamine, 0=placebo
age
Age in years (days divided by 365.25)
sex
Sex, 0=male, 1=female
asc
Presence of ascites, 0=no, 1=yes
hep
Presence of hepatomegaly, 0=no, 1=yes
spi
Presence of spiders, 0=no, 1=yes
ede
Presence of edema, 0=no edema, 0.5=edema resolved by therapy, 1=edema not resolved by therapy
bil
log(bililubin, mg/dl)
cho
log(cholesterol, mg/dl)
alb
log(albumin, gm/dl)
cop
log(urine copper, mg/day)
alk
log(alkarine, U/liter)
SGO
log(SGOT, in U/ml)
tri
log(triglycerides, in mg/dl)
pla
log(platelet count, [the number of platelets per-cubic-milliliter of blood]/1000)
pro
log(prothrombin time, in seconds)
gra
Histologic stage of disease, graded 1, 2, 3, or 4
Details
Survival data consisting of 276 patients with 17 covariates. Among them, 111 patients died (d=1) while others were censored (d=0). The covariates consist of a treatment indicator (trt), age, sex, 5 categorical variables (ascites, hepatomegaly, spider, edema, and stage of disease) and 9 log-transformed continuous variables (bilirubin, cholesterol, albumin, urine copper, alkarine, SGOT, triglycerides, platelet count, and prothrombine).
Source
Fleming & Harrignton (1991); Tibshirani (1997)
References
Tibshirani R (1997), The Lasso method for variable selection in the Cox model, Statistics in Medicine, 385-395.
Examples
data(PBC)
PBC[1:5,] ### profiles for the first 5 patients ###
# See also Appendix D.1 of Fleming & Harrington, Counting Process & Survival Analysis (1991) #