This dataset gives the longitudinal observations of prothrombin index, a measure of liver function, for patients from a controlled trial into prednisone treatment of liver cirrhosis. Time-to-event information in the form of the event time and associated censoring indicator are also recorded along with a solitary baseline covariate - the allocated treatment arm in this instance. The data are taken from Andersen et al. (1993, p. 19) and were analyzed in Henderson et al. (2002). This is a subset of the full data where a number of variables were recorded both at entry and during the course of the trial.
data(liver)
A data.frame
in the unbalanced format with longitudinal observations
from 488 subjects. The columns are:
id
integer: number for patient identification.
prothrombin
integer: prothrombin index measurement (%).
time
numeric: time of prothrombin index measurement (years).
treatment
integer: patient treatment indicator. Coded as
0 =
placebo; 1 =
prednisone.
survival
numeric: patient survival time (years).
cens
integer: censoring indicator. Coded as 1 =
died;
0 =
censored.
Andersen PK, Borgan O, Gill RD, Kieding N. Statistical Models Based on Counting Processes. New York: Springer. 2003.
Henderson R, Diggle PJ, Dobson A. Identification and efficacy of longitudinal markers for survival. Biostatistics 2002; 3: 33-50.
heart.valve
, epileptic
,
mental
, aids
.