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The LIFETEST Procedure

Syntax

The following statements are available in PROC LIFETEST:

PROC LIFETEST < options > ;
TIME variable < *censor(list) > ;
BY variables ;
FREQ variable ;
ID variables ;
STRATA variable < (list) > < ... variable < (list) > > ;
TEST variables ;

The simplest use of PROC LIFETEST is to request the nonparametric estimates of the survivor function for a sample of survival times. In such a case, only the PROC LIFETEST statement and the TIME statement are required. You can use the STRATA statement to divide the data into various strata. A separate survivor function is then estimated for each stratum, and tests of the homogeneity of strata are performed. You can specify covariates in the TEST statement. PROC LIFETEST computes linear rank statistics to test the effects of these covariates on survival.

The PROC LIFETEST statement invokes the procedure. All statements except the TIME statement are optional, and there is no required order for the statements following the PROC LIFETEST statement. The TIME statement is used to specify the variables that define the survival time and censoring indicator. The STRATA statement specifies a variable or set of variables defining the strata for the analysis. The TEST statement specifies a list of numeric covariates to be tested for their association with the response survival time. Each variable is tested individually, and a joint test statistic is also computed. The ID statement provides a list of variables whose values are used to identify observations in the product-limit estimates of the survival function. When only the TIME statement appears, no strata are defined and no tests of homogeneity are performed.


PROC LIFETEST Statement

BY Statement

FREQ Statement

ID Statement

STRATA Statement

TEST Statement

TIME Statement

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