Biomedical Engineering Reference
In-Depth Information
out : name of output file to store the MCMC samples.
model : model type to fit. The three options, TimeIndep , TimeVarying ,
and Dynamic , correspond to the Cox proportional hazards model, the
time-varying-coecient Cox model (Sinha et al., 1999), and the dynamic
Cox model (Wang et al., 2011a), respectively.
base.prior : list of options for prior of baseline hazards.
coef.prior : list of options for prior of regression coecients.
gibbs : list of options for Gibbs sampler.
control : list of general control options.
More detailed documentations and working examples are available at the help
page of function bayesCox in the package.
7.6
Simulation Study
A simulation study was carried out to assess the recovery of true coecients
and the performance of the model selection criteria. We considered a situation
with only a binary covariate X, which follows a Bernoulli distribution with
rate parameter 0.5. Data sets of sample size n = 400 were generated from
model (7.1) with two specications for regression coecient (t): (t) = 1
and (t) = 0:5 + sin(t=6). The baseline hazard function is 0 (t) = 0:1 p (t).
The time interval of interest is set as (0; 6).
Interval-censored survival times were generated in two steps. In the first
step, the exact event time T was generated given X, (t), and 0 (t) by solving
F(T) = U, where F is the distribution function of T, and U is an indepen-
dent uniform variable over (0; 1). In the second step, a censoring interval was
generated. For each subject, we generated gap times as visit schedule until
 
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