gehan                  package:MASS                  R Documentation

_R_e_m_i_s_s_i_o_n _T_i_m_e_s _o_f _L_e_u_k_a_e_m_i_a _P_a_t_i_e_n_t_s

_D_e_s_c_r_i_p_t_i_o_n:

     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  The trial was designed as matched pairs, both withdrawn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.

_U_s_a_g_e:

     gehan

_F_o_r_m_a_t:

     This data frame contains the following columns:

     '_p_a_i_r' label for pair.

     '_t_i_m_e' remission time in weeks.

     '_c_e_n_s' censoring, 0/1.

     '_t_r_e_a_t' treatment, control or 6-MP.


_S_o_u_r_c_e:

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

     Gehan, E.A. (1965) A generalized Wilcoxon test for comparing
     arbitrarily single-censored samples. _Biometrika_ *52*, 203-233.

_R_e_f_e_r_e_n_c_e_s:

     Venables, W. N. and Ripley, B. D. (2002) _Modern Applied
     Statistics with S._ Fourth edition.  Springer.

_E_x_a_m_p_l_e_s:

     library(survival)
     gehan.surv <- survfit(Surv(time, cens) ~ treat, data = gehan,
          conf.type = "log-log")
     summary(gehan.surv)
     survreg(Surv(time, cens) ~ factor(pair) + treat, gehan, dist = "exponential")
     summary(survreg(Surv(time, cens) ~ treat, gehan, dist = "exponential"))
     summary(survreg(Surv(time, cens) ~ treat, gehan))
     gehan.cox <- coxph(Surv(time, cens) ~ treat, gehan)
     summary(gehan.cox)