Data from a trial of usrodeoxycholic acid
Data from a trial of ursodeoxycholic acid (UDCA) in patients with primary biliary cirrohosis (PBC).
udca udca2 data(udca, package="survival")
A data frame with 170 observations on the following 15 variables.
idsubject identifier
trttreatment of 0=placebo, 1=UDCA
entry.dtdate of entry into the study
last.dtdate of last on-study visit
stagestage of disease
bilibilirubin value at entry
riskscorethe Mayo PBC risk score at entry
death.dtdate of death
tx.dtdate of liver transplant
hprogress.dtdate of histologic progression
varices.dtappearance of esphogeal varices
ascites.dtappearance of ascites
enceph.dtappearance of encephalopathy
double.dtdoubling of initial bilirubin
worsen.dtworsening of symptoms by two stages
This data set is used in the Therneau and Grambsh. The udca1
data set contains the baseline variables along with the time until the
first endpoint (any of death, transplant, ..., worsening).
The udca2 data set treats all of the endpoints as parallel
events and has a stratum for each.
T. M. Therneau and P. M. Grambsch, Modeling survival data: extending the Cox model. Springer, 2000.
K. D. Lindor, E. R. Dickson, W. P Baldus, R.A. Jorgensen, J. Ludwig, P. A. Murtaugh, J. M. Harrison, R. H. Weisner, M. L. Anderson, S. M. Lange, G. LeSage, S. S. Rossi and A. F. Hofman. Ursodeoxycholic acid in the treatment of primary biliary cirrhosis. Gastroenterology, 106:1284-1290, 1994.
# values found in table 8.3 of the book
fit1 <- coxph(Surv(futime, status) ~ trt + log(bili) + stage,
cluster =id , data=udca1)
fit2 <- coxph(Surv(futime, status) ~ trt + log(bili) + stage +
strata(endpoint), cluster=id, data=udca2)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.