Calculates the life-table estimate of the survivor function (D.A.Murray).
Options
PRINT = string tokens |
Controls printed output (lifetable); default life |
|---|---|
PLOT = string tokens |
Type of graph to be plotted (survivor, hazard, pdf); default surv, haza, pdf |
INTERVAL = scalar or variate |
A scalar defining the width of the intervals or a variate containing the boundaries of the intervals |
Parameters
TIMES = variates |
Observed timepoints |
|---|---|
CENSORED = variates |
Variate specifying whether the corresponding element of each TIMES variate is censored (1) or represents failures (0) |
FREQUENCY = variates |
Variate containing frequencies for the elements of TIMES; by default these are all assumed to be 1 |
GROUPS = factors |
Factor specifying the different groups for which to estimate life tables |
LIFETABLE = pointers |
Pointer to variates to save the information from each life table |
Description
RLIFETABLE calculates the life-table estimate, or actuarial estimate, of the survivor function. The life-table method requires a fairly large number of observations so that survival times can be grouped into intervals. These are specified using the INTERVALS option. For equal intervals, you can set INTERVALS to a scalar to define their width. Alternatively you can set INTERVALS to a variate containing the lower boundaries of the intervals. The PLOT option can be used to produce plots of the survivor function (survivor), estimated hazard function (hazard) and the probability density function (pdf). You can set the option PRINT=* to suppress printing of the life table; by default PRINT=lifetable.
The observed timepoints (or the timepoints at which censoring took place) are specified using the TIMES parameter. The CENSORED parameter specifies a variate containing the value one if the corresponding element of TIMES is censored or zero if it was not. CENSORED can be omitted if there was no censoring. If there are several observations (all censored or all uncensored) at a time point, you can specify the time point only once and define the number of observations by specifying a variate of counts using the FREQUENCY parameter. This is particularly useful if the contents of the TIMES variate are intended to identify time intervals rather than discrete time points. The GROUPS parameter can be used to request separate life tables for different groups of data. The LIFETABLE parameter allows the life table to be saved in a pointer to a set of variates for each of the columns within the table.
Options: PRINT, PLOT, INTERVAL.
Parameters: TIMES, CENSORED, FREQUENCY, GROUPS, LIFETABLE.
Method
The methodology in RLIFETABLE is based on that described in Chapter 4 of Lee (1992).
Action with RESTRICT
The input variates and factors may be restricted identically. The life tables are based only on the units not excluded by the restriction.
Reference
Lee, E.T. (1992). Statistical Methods for Survival Data Analysis. Wiley, New York.
See also
Procedures: KAPLANMEIER, RPHFIT, RPROPORTIONAL, RSTEST, RSURVIVAL.
Commands for: Survival analysis.
Example
CAPTION 'RLIFETABLE example',\
!t('Survival data for 2418 male patients with angina pectoris',\
'(Lee 1992, page 91).'); STYLE=meta,plain
VARIATE [NVALUES=32] Time; VALUES=!((0.5...15.5)2)
& Censor; VALUES=!(16(0,1))
& Count; VALUES=!(456,226,152,171,135,125,83,74,51,42,43,34,18,9,6,0,\
0,39,22,23,24,107,133,102,68,64,45,53,33,27,23,30)
RLIFETABLE [INTERVAL=!(0...15)] Time; CENSORED=Censor; FREQUENCY=Count;\
LIFETABLE=Ltab