VARIABLES Subcommand (CSCOXREG command)

VARIABLES specifies the status variable, ID variable, and baseline strata variable.

STATUS = varname. Event status variable. To determine whether the event has occurred at endtime for a particular observation, CSCOXREG checks the value of a status variable. STATUS lists the status variable and the values that indicate the occurrence of the event.

  • The value list must be enclosed in parentheses. All cases with non-negative times that do not have a value within the range specified are classified as censored cases—that is, cases for which the event has not yet occurred at endtime.
  • The value list can be one value, a list of values separated by blanks or commas, a range of values using the keyword THRU, or a combination.
  • The status variable can be either numeric or string. If a string variable is specified, the event values must be enclosed in apostrophes and the keyword THRU cannot be used.
  • ID variable. Cases with the same ID value are repeated observations from the same subject. If ID is not specified, each case represents one subject.

BASELINESTRATA = varname. Baseline stratification variable. A separate baseline hazard and survival function is computed for each value of this variable, while a single set of model coefficients is estimated across strata.

Example

CSCOXREG SURVIVAL by GROUP
/VARIABLES STATUS=SURVSTA(3 THRU 5, 8 THRU 10) BASELINESTRATA=LOCATION
/PLAN FILE=’c:\survey\myfile.csplan’.
  • STATUS specifies that SURVSTA is the status variable.
  • A value between either 3 and 5 or 8 and 10, inclusive, means that the terminal event occurred.
  • Values outside the specified ranges indicate censored cases.
  • BASELINESTRATA specifies LOCATION as the strata variable.
  • Different baseline survival functions are computed for each value of LOCATION.