The LIFETEST Procedure

ODS Graphics

Subsections:

Additional Dynamic Variables for Survival Plots Using ODS Graphics

Statistical procedures use ODS Graphics to create graphs as part of their output. ODS Graphics is described in detail in Chapter 21: Statistical Graphics Using ODS.

Before you create graphs, ODS Graphics must be enabled (for example, by specifying the ODS GRAPHICS ON statement). For more information about enabling and disabling ODS Graphics, see the section Enabling and Disabling ODS Graphics in Chapter 21: Statistical Graphics Using ODS.

The overall appearance of graphs is controlled by ODS styles. Styles and other aspects of using ODS Graphics are discussed in the section A Primer on ODS Statistical Graphics in Chapter 21: Statistical Graphics Using ODS.

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 70.7, along with the required keywords for the PLOTS= option.

Table 70.7: Graphs Produced by PROC LIFETEST

ODS Graph Name	Plot Description	PLOTS= Option
cifPlot	Cumulative incidence function	CIF
cifPlot	Cumulative incidence function with pointwise confidence limits	CIF(CL)
cifPlot	Cumulative incidence function with Gray’s test	CIF(TEST)
DensityPlot	Density function for life-table method	PDF
FailurePlot	Cumulative distribution function	survival (FAILURE )
HazardPlot	Hazard function for life-table method or smoothed hazard for product-limit, Breslow, or Fleming-Harrington method	HAZARD
LogNegLogSurvivalPlot	Log(-log(survivor function)	LOGLOGS
NegLogSurvivalPlot	Log(survivor function)	LOGSURV
SurvivalPlot	Survivor function	SURVIVAL
SurvivalPlot	Survivor function with number of subjects at risk	SURVIVAL (ATRISK )
SurvivalPlot	Survivor function with pointwise confidence limits	SURVIVAL (CL )
SurvivalPlot	Survivor function with equal-precision band	SURVIVAL (CB=EP )
SurvivalPlot	Survivor function with Hall-Wellner band	SURVIVAL (CB=HW )
SurvivalPlot	Survivor function with homogeneity test	SURVIVAL (TEST )

Additional Dynamic Variables for Survival Plots Using ODS Graphics

PROC LIFETEST passes a number of summary statistics as dynamic variables to the ODS Graphics for survival plots. Table 70.8 and Table 70.9 list these additional dynamic variables for the Kaplan-Meier curves and the life-table 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.

Table 70.8: Additional Dynamic Variables for Stat.Graphics.ProductLimitSurvival

STRATA=	Dynamic	Description
OVERLAY	StrValj	Label for the jth stratum
	NObsj	Number of observations in the jth stratum
	NEventj	Number of events in the jth stratum
	Medianj	Median survival time of the jth stratum
	LowerMedianj	Lower median survival time of the jth stratum
	UpperMedianj	Upper median survival time of the jth stratum
	PctMedianConfid	Confidence of the median intervals in percent
INDIVIDUAL	NObs	Number of observations
	NEvent	Number of events
	Median	Median survival time
	LowerMedian	Lower median survival time
	UpperMedian	Upper median survival time
	PctMedianConfid	Confidence of the median interval in percent

Table 70.9: Additional Dynamic Variables for Stat.Graphics.LifetableSurvival

STRATA=	Dynamic	Description
OVERLAY	StrValj	Label for the jth stratum
	NObsj	Number of observations in the jth stratum
	NEventj	Number of events in the jth stratum
INDIVIDUAL	NObs	Number of observations
	NEvent	Number of events

For information about all of the dynamic variables that are available for use in the ODS Graphics survival plot, see the section Dynamic Variables in Chapter 23: Customizing the Kaplan-Meier Survival Plot. For the use of the particular dynamic variables shown in this section, see the sections Adding a Small Inset Table with Event Information and Adding an External Table with Event Information in Chapter 23: Customizing the Kaplan-Meier Survival Plot.