The LIFETEST Procedure |
ODS Graphics |
To request graphics with PROC LIFETEST, you must first enable ODS Graphics by specifying the ods graphics on statement. See Chapter 21, Statistical Graphics Using ODS, for more information. The survival plot is produced by default; other graphs are produced by using the PLOTS= option in the PROC LIFETEST statement. You can reference every graph produced through ODS Graphics with a name. The names of the graphs that PROC LIFETEST generates are listed in Table 49.5, along with the required keywords for the PLOTS= option.
ODS Graph Name |
Plot Description |
PLOTS=Option |
---|---|---|
DensityPlot |
Estimated density for life-table method |
|
FailurePlot |
Estimated failure function |
|
HazardPlot |
Estimated hazard function for life-table method or smoothed hazard for product-limit method |
|
LogNegLogSurvivalPlot |
Log of negative log of the estimated survivor function |
|
NegLogSurvivalPlot |
Negative log of the estimated survivor function |
|
SurvivalPlot |
Estimated survivor function |
|
SurvivalPlot |
Estimated survivor function with number of subjects at risk |
|
SurvivalPlot |
Estimated survivor function with pointwise confidence limits |
|
SurvivalPlot |
Estimated survivor function with equal-precision band |
|
SurvivalPlot |
Estimated survivor function with Hall-Wellner band |
|
SurvivalPlot |
Estimated survivor function with homogeneity test p-value |
PROC LIFETEST passes a number of summary statistics as dynamic variables to the ODS Graphics for survival plots. Table 49.6 and Table 49.7 list these additional dynamic variables for the Kaplan-Meier curves and the lifetable curves, respectively. These dynamic variables are not declared in the templates for the survival curves, but you can declare them and use them to enhance the default plots. The names of the dynamic variables depend on the STRATA= suboption of the PLOTS=SURVIVAL option: STRATA=INDIVIDUAL produces a separate plot for each stratum, and STRATA=OVERALL produces one plot with overlaid curves.
STRATA= |
Dynamic |
Description |
---|---|---|
OVERLAY |
StrVal |
Label for the th stratum |
NObs |
Number of observations in the th stratum |
|
NEvent |
Number of events in the th stratum |
|
Median |
Median survival time of the th stratum |
|
LowerMedian |
Lower median survival time of the th stratum |
|
UpperMedian |
Upper median survival time of the th stratum |
|
pctMedianConfid |
Percent confidence of the median intervals |
|
INDIVIDUAL |
NObs |
Number of observations |
NEvent |
Number of events |
|
Median |
Median survival time |
|
LowerMedian |
Lower median survival time |
|
UpperMedian |
Upper median survival time |
|
pctMedianConfid |
Percent confidence of the median interval |
STRATA= |
Dynamic |
Description |
---|---|---|
OVERLAY |
StrVal |
Label for the th stratum |
NObs |
Number of observations in the th stratum |
|
NEvent |
Number of events in the th stratum |
|
INDIVIDUAL |
NObs |
Number of observations |
NEvent |
Number of events |
See the section The Graph Template Language and Example 21.5 in Chapter 21, Statistical Graphics Using ODS, for more information about dynamic variables and ODS Graphics.
Copyright © 2009 by SAS Institute Inc., Cary, NC, USA. All rights reserved.