udca
Data from a trial of usrodeoxycholic acid
Description
Data from a trial of ursodeoxycholic acid (UDCA) in patients with primary biliary cirrohosis (PBC).
Usage
udca udca2 data(udca, package="survival")
Format
A data frame with 170 observations on the following 15 variables.
-
id
-
subject identifier
-
trt
-
treatment of 0=placebo, 1=UDCA
-
entry.dt
-
date of entry into the study
-
last.dt
-
date of last on-study visit
-
stage
-
stage of disease
-
bili
-
bilirubin value at entry
-
riskscore
-
the Mayo PBC risk score at entry
-
death.dt
-
date of death
-
tx.dt
-
date of liver transplant
-
hprogress.dt
-
date of histologic progression
-
varices.dt
-
appearance of esphogeal varices
-
ascites.dt
-
appearance of ascites
-
enceph.dt
-
appearance of encephalopathy
-
double.dt
-
doubling of initial bilirubin
-
worsen.dt
-
worsening of symptoms by two stages
Details
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.
References
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.
Examples
# 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)
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Licensed under the GNU General Public License.