liver: Prednisone versus Placebo in Liver Cirrhosis Patients

In JSM: Semiparametric Joint Modeling of Survival and Longitudinal Data

Description

A randomized control trial in which both survival and longitudinal data were collected to examine the development of prothrombin index over time and its relationship with the survival outcome. 488 patients were randomly allocated to prednisone (251) or placebo (237) and followed until death or end of the study.

Format

A data frame with 2968 observations on the following 9 variables.

ID

patient ID, there are 488 patients in total.

Time

survival time, i.e. time to death or censoring.

death

death indicator: 0 denotes censoring; 1 denotes death.

obstime

time points at which the longitudinal measurements, i.e. prothrombin index, are recorded.

proth

prothrombin index measured at obstime.

Trt

treatment indicator with two levels: placebo and prednisone.

start

same with obstime, starting time of the interval which contains the time of the prothrombin index measurement.

stop

ending time of the interval which contains the time of the prothrombin index measurement.

event

event indicator suggesting whether the event-of-interest, i.e. death, happens in the interval given by start and stop.

Source

Andersen, P. K., Borgan O., Gill, R. D. and Kieding, N. (1993) Statistical Models Based on Counting Processes. New York: Springer.

References

Henderson, R., Diggle, P. and Dobson, A. (2002) Identification and efficacy of longitudinal markers for survival. Biostatistics 3, 33–50

See Also

liver.long, liver.surv

Examples

head(liver)

Example output

Loading required package: nlme
Loading required package: splines
Loading required package: statmod
Loading required package: survival

Attaching package: 'JSM'

The following object is masked from 'package:survival':

    pbc

  ID      Time death   obstime proth     Trt     start      stop event
1  1 0.4134268     1 0.0000000    38 placebo 0.0000000 0.2436754     0
2  1 0.4134268     1 0.2436754    31 placebo 0.2436754 0.3805717     0
3  1 0.4134268     1 0.3805717    27 placebo 0.3805717 0.4134268     1
4  2 6.7544628     1 0.0000000    51 placebo 0.0000000 0.6872194     0
5  2 6.7544628     1 0.6872194    73 placebo 0.6872194 0.9610119     0
6  2 6.7544628     1 0.9610119    90 placebo 0.9610119 1.1882598     0

JSM documentation built on Sept. 4, 2020, 1:08 a.m.