A TWO-SAMPLE COMPARISON FOR MULTIPLE ORDERED EVENT DATA
Resource
BIOMETRICS v.56 n.1 pp.183-189
Journal
BIOMETRICS
Journal Volume
v.56
Journal Issue
n.1
Pages
183-189
Date Issued
2000
Date
2000
Author(s)
CHANG, SHU-HUI
Abstract
A longitudinal study is conducted tu compare the process of
a particular disease between two groups. The process of the
disease is monitored according to which of several ordered
events occur. In the paper, the sojourn time between two
successive events is considered as the outcome of interest.
The group effects on the sojourn times of the multiple
events are parameterized by scale changes in a
semiparametric accelerated failure time model where the
dependence structure among the multivariate sojourn times is
unspecified. Suppose that the sojourn times are subject to
dependent censoring and the censoring times are observed for
all subjects. A log-rank-type estimating approach by
rescaling the sojourn times and the dependent censoring
times into the same distribution is constructed to estimate
the group effects and the corresponding estimators are
consistent and asymptotically normal. Without the dependent
censoring, the independent censoring times in general are
not available for the uncensored data. In order to complete
the censoring information, pseudo-censoring times are
generated from the corresponding nonparametrically estimated
survival function in each group, and we can still obtained
unbiased estimating functions for the group effects. A real
application and a simulation study are conducted to
illustrate the proposed methods.
Subjects
accelerated failure time model
correlated failure time
informative censoring
log-rank statistic
Type
journal article