

   RReemmiissssiioonn TTiimmeess ooff LLeeuukkaaeemmiiaa PPaattiieennttss

   AArrgguummeennttss::

       pair: label for pair

       time: remission time in weeks

       cens: censoring, 0/1

      treat: treatment, control or 6-MP

   SSUUMMMMAARRYY::

        A data frame from a trial of 42 leukaemia patients.
        Some were treated with the drug 6-mercaptopurine and
        the rest are controls.  The trial was designed as
        matched pairs, both withdrawn from the trial when
        either came out of remission.

   DDAATTAA DDEESSCCRRIIPPTTIIOONN::

        This data frame contains the following columns:

   SSOOUURRCCEE::

        D.R. Cox and D. Oakes (1984) Analysis of Survival Data.
        Chapman  Hall, p. 7. Taken from

        Gehan, E.A. (1965) A generalized Wilcoxon test for com-
        paring arbitrarily single-censored samples.  Biometrika
        52, 203-233.

   EExxaammpplleess::

        library(survival4)
        data(gehan)
        attach(gehan)
        gehan.surv <- survfit(Surv(time, cens) ~ treat)
        gehan.surv
        plot(gehan.surv, conf.int=T, lty=c(3,4), log=T,
           xlab="time of remission (weeks)", ylab="survival")
        gehan.exp <- survreg(Surv(time, cens) ~ treat + factor(pair), dist="exp")
        summary(gehan.exp)
        gehan.exp <- survreg(Surv(time, cens) ~ treat, dist="exp")
        summary(gehan.exp)
        gehan.wei <- survreg(Surv(time, cens) ~ treat)
        summary(gehan.wei)
        gehan.cox <- coxph(Surv(time, cens) ~ treat)
        summary(gehan.cox)

