frailty(x, distribution="gamma", ...)
"gamma",
"gaussian", and
"t".
coxph or
survReg.
this routine calls
frailty.gamma,
frailty.gaussian, or
frailty.t to do
the actual work.
When using frailty terms with a
survReg model,
only
method="aic" should be used.
The
method argument can be set
in the call to
frailty in the formula.
The
method argument will be passed down to the specific
frailty function via the
... argument.
coxph(Surv(time, status) ~ age + sex + frailty(inst), data=lung,
na.action=na.exclude)