summary.survfit           package:survival           R Documentation

_S_u_m_m_a_r_y _o_f _a _S_u_r_v_i_v_a_l _C_u_r_v_e

_D_e_s_c_r_i_p_t_i_o_n:

     Returns a list containing the survival curve, confidence limits
     for the  curve, and other information.

_U_s_a_g_e:

       ## S3 method for class 'survfit':
       summary(object, times=, censored=FALSE, scale=1,
       extend=FALSE, rmean=getOption('survfit.rmean'), ...)
       

_A_r_g_u_m_e_n_t_s:

  object: the result of a call to the 'survfit' function.  

   times: vector of times;  the returned matrix will contain 1 row for
          each time.  This must be in increasing order and missing
          values are not allowed.  If 'censored=T', the default 'times'
          vector contains all the unique times in 'fit', otherwise the
          default 'times' vector uses only the event (death) times.  

censored: logical value:  should the censoring times be included in the
          output? This is ignored if the 'times' argument is present.  

   scale: numeric value to rescale the survival time, e.g., if the
          input data to  'survfit' were in  days, 'scale = 365.25'
          would scale the output to years.  

  extend: logical value: if TRUE, prints information for all specified
          'times',  even if there are no subjects left at the end of
          the specified 'times'.  This is only valid if the 'times'
          argument is present.  

   rmean: Show restricted mean: see 'print.summary.survfit' for details

     ...: for future methods

_V_a_l_u_e:

     a list with the following components: 

    surv: the estimate of survival at time t+0.  

    time: the timepoints on the curve.  

  n.risk: the number of subjects at risk at time t-0  (but see the
          comments on weights in the 'survfit' help file).  

 n.event: if the 'times' argument is missing, then this column is the
          number of  events that occurred at time t.  Otherwise, it is
          the cumulative number of events that have occurred  since the
          last time listed until time t+0.  

n.entered: This is present only for counting process survival data. If
          the 'times' argument is  missing, this column is the number
          of subjects that entered at time t.  Otherwise, it is the
          cumulative number of subjects that have entered  since the
          last time listed until time t.   

n.exit.censored: if the 'times' argument is  missing, this column is
          the number of subjects that left without an  event at time t.
           Otherwise, it is the cumulative number of subjects that have
          left  without an event  since the last time listed until time
          t+0.   This is only present for counting process survival
          data. 

 std.err: the standard error of the survival value.  

conf.int: level of confidence for the confidence intervals of survival.            

   lower: lower confidence limits for the curve.  

   upper: upper confidence limits for the curve.  

  strata: indicates stratification of curve estimation.   If 'strata'
          is not 'NULL',  there are multiple curves in the result and
          the 'surv', 'time', 'n.risk', etc.   vectors will contain
          multiple curves, pasted end to end.   The levels of 'strata'
          (a factor) are the labels for the curves.  

    call: the statement used to create the 'fit' object.  

na.action: same as for 'fit', if present.  

   table: table of information that is returned from 'print.survfit'
          function.  

    type: type of data censoring.  Passed through from the fit object.  

_S_e_e _A_l_s_o:

     'survfit',  'print.summary.survfit'

_E_x_a_m_p_l_e_s:

     summary( survfit( Surv(futime, fustat)~1, data=ovarian))
     summary( survfit( Surv(futime, fustat)~rx, data=ovarian))