\HeaderA{kidney}{Kidney data from survival5}{kidney}
\keyword{survival}{kidney}
\begin{Description}\relax
Data on the recurrence times to infection, at the point of insertion of
the catheter, for kidney patients using portable dialysis equipment.
Catheters may be removed for reasons other than infection, in which case
the observation is censored.  Each patient has exactly 2 observations.
\end{Description}
\begin{Format}\relax
\Tabular{ll}{
patient:& id\\
time:& time\\
status:& event status\\
age:& in years\\
sex:& 1=male, 2=female\\
disease:&  disease type (0=GN, 1=AN, 2=PKD, 3=Other)\\
frail:& frailty estimate from original paper\\
}
\end{Format}
\begin{Section}{Note}
The original analysis had incorrect handling of ties and so is not
exactly reproduced by survival.
\end{Section}
\begin{Source}\relax
CA McGilchrist, CW Aisbett (1991),
Regression with frailty in survival analysis. 
\emph{Biometrics} \bold{47}, 461--66.
\end{Source}
\begin{Examples}
\begin{ExampleCode}
kfit <- coxph(Surv(time, status)~ age + sex + disease + frailty(id), kidney)
kfit0 <- coxph(Surv(time, status)~ age + sex + disease, kidney)
kfitm1 <- coxph(Surv(time,status) ~ age + sex + disease + 
                frailty(id, dist='gauss'), kidney)

\end{ExampleCode}
\end{Examples}

