The ICLIFETEST Procedure


The main features of the ICLIFETEST procedure are as follows:

  • Nonparametric estimation

    • uses the efficient EMICM algorithm (Wellner and Zhan, 1997) to estimate survival functions by default

    • supports Turnbull’s algorithm (Turnbull, 1976) and the iterative convex minorant (ICM) algorithm (Groeneboom and Wellner, 1992)

    • computes standard errors of the survival estimates by using a multiple imputation method or a bootstrap method

    • supports several transformation-based confidence intervals

    • produces survival plots

  • Survival comparisons

    • provides the weighted generalized log-rank test

    • supports a variety of weight functions for testing early or late differences

    • supports a stratified test for survival differences within predefined populations

    • supports a trend test for ordered alternatives

    • supports multiple-comparison functionalities

The ICLIFETEST procedure uses ODS Graphics to create graphs as part of its output. For general information about ODS Graphics, see Chapter 21: Statistical Graphics Using ODS.