The ICPHREG Procedure

STRATA Statement

  • STRATA variable </ option>;

The proportional hazards assumption might not be realistic for all data. However, it might still be reasonable to perform a stratified analysis. The STRATA statement names one variable that determines the stratification. Strata are formed according to the nonmissing values of the STRATA variables unless you specify the MISSING option in the CLASS statement. In the STRATA statement, variable is a variable whose values are used to determine the strata levels. Multiple variables can appear in the STRATA statement.

You can specify the following option:


allows missing values (‘.’ for numeric variables and blanks for character variables) as valid STRATA variable values. Otherwise, observations that have missing STRATA variable values are deleted from the analysis.