Statistical Analysis of Dependent Current Status Data with Application to Tumorigenicity Experiments - Interval-Censored-Time-to-Event Data: Methods and Applications - page 121

The argument data corresponds to an input data set. It consists of five
columns whose names are id , time , tumor , death , and trt . The column id
in data denotes an identification number, time a death time or a sacrifice
time, tumor a 0-1 indicator whether or not a tumor onset occurs (0: without
a tumor onset, 1: with a tumor onset), death a 0-1 indicator whether or
not a death occurs (0: sacrificed, 1: died), and trt a binary covariate. The
argument int is breaking time points for piece and does not include time
points 0 and the maximum time which is set in advance. For example, when
the maximum observed value is 12, int=c(3,6,9) implies that the interval
(0,12] is split into four sub-intervals such as (0,3], (3,6], (6,9], (9,12]. In the
argument frailty , we can choose ` gamma ' to t a gamma frailty model or
` normal ' to t a normal frailty model. Here, the gamma and normal frailties
follow G( 1 ;) and N(0;); respectively. The argument init denotes the
initial value of each parameter (default = 0 for 1 ; 2 ; and 3 ; 0.1 for 01 (t)
and 02 (t); and 1 for ); and the argument tol the convergence criterion of
EM algorithm (default = 0.001). Finally, the argument plots requires that
we plot the estimates of 1 ; 2 ; 3 ; and through the EM algorithm until the
convergence criterion is satisfied (default = F).
For a chosen frailty, the packageCSD, by default, produces the estimates
for the regression parameters, 1 ; 2 ; and 3 ; the baseline hazard rates for
tumor onset time and death time, 01 (t) and 02 (t); and (denoted as
Estimate ) along with their standard errors (denoted as SE ), the 95% con-
fidence limits (denoted as (L,U) ), test statistic (denoted as Z ), and the result-
ing p-values (denoted as P-value ). Finally, it provides the values of the full
log-likelihood and sample size used in the analysis.