Output Data Sets
OUTSURV= Data Set
The OUTSURV= option in the LIFETEST statement creates
an output data set containing survival estimates.
It contains
- any specified BY variables
- any specified STRATA variables, their values coming
from either their original values or the midpoints
of the stratum intervals if endpoints are used to
define strata (semi-infinite intervals are labeled
by their finite endpoint)
- _STRTUM_, a numeric variable that numbers the strata
- the time variable as given
in the TIME statement.
In the case of the product-limit estimates, it
contains the observed failure or censored times.
For the life table estimates, it contains
the lower endpoints of the time intervals.
- SURVIVAL, a variable containing
the survival function estimates
- SDF_LCL, a variable containing the lower
endpoint of the survival confidence interval
- SDF_UCL, a variable containing the upper
endpoint of the survival confidence interval
If the estimation uses the product-limit method,
then the data set also contains
- _CENSOR_, an indicator variable that has a value 1 for a
censored observation and a value 0 for an event observation
If the estimation uses the life table method,
then the data set also contains
- MIDPOINT, a variable containing the value
of the midpoint of the time interval
- PDF, a variable containing the density function estimates
- PDF_LCL, a variable containing the lower
endpoint of the PDF confidence interval
- PDF_UCL, a variable containing the upper
endpoint of the PDF confidence interval
- HAZARD, a variable containing the hazard estimates
- HAZ_LCL, a variable containing the lower
endpoint of the hazard confidence interval
- HAZ_UCL, a variable containing the upper
endpoint of the hazard confidence interval
Each survival function contains an initial observation
with the value 1 for the SDF and the value 0 for the time.
The output data set contains an observation for each distinct
failure time if the product-limit method
is used or an observation for each time
interval if the life table method is used.
The product-limit survival estimates are defined to be
right continuous; that is, the estimates at a given time include
the factor for the failure events that occur at that time.
Labels are assigned to all the variables in the output
data set except the BY variable and the STRATA variable.
OUTTEST= Data Set
The OUTTEST= option in the LIFETEST statement creates
an output data set containing the rank statistics for
testing the association of failure time with covariates.
It contains
- any specified BY variables
- _TYPE_, a character variable of length 8
that labels the type of rank test, either
"LOG-RANK" or "WILCOXON"
- _NAME_, a character variable of length 8 that labels
the rows of the covariance matrix and the test statistics
- the TIME variable, containing the overall test statistic
in the observation that has _NAME_ equal to the name
of the time variable and the univariate test statistics
under their respective covariates.
- all variables listed in the TEST statement
The output is in the form of a symmetric matrix formed by
the covariance matrix of the rank statistics bordered by
the rank statistics and the overall chi-square statistic.
If the value of _NAME_ is the name of a variable
in the TEST statement, the observation contains
a row of the covariance matrix and the value of
the rank statistic in the time variable.
If the value of _NAME_ is the name of the TIME variable,
the observation contains the values of the rank statistics
in the variables from the TEST list and the value of the
overall chi-square test statistic in the TIME variable.
Two complete sets of statistics labeled by
the _TYPE_ variable are produced, one for the
log-rank test and one for the Wilcoxon test.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.
