STATUS Subcommand (KM command)

To determine whether the terminal event has occurred for a particular observation, KM checks the value of a status variable. STATUS lists the status variable and the code(s) for the occurrence of the event. The code(s) for cases lost to follow-up can also be specified.

  • Only one status variable can be specified. If multiple STATUS subcommands are specified, KM uses the last specification and displays a warning.
  • The keyword EVENT is optional, but the value list in parentheses must be specified. Use EVENT for clarity’s sake, especially when LOST is specified.
  • The value list must be enclosed in parentheses. All cases with non-negative times that do not have a code within the range specified after EVENT are classified as censored cases—that is, cases for which the event has not yet occurred.
  • The keyword LOST and the following value list are optional. LOST cannot be omitted if the value list for lost cases is specified.
  • When LOST is specified, all cases with non-negative times that have a code within the specified value range are classified as lost to follow-up. Cases lost to follow-up are treated as censored in the analysis, and the statistics do not change, but the two types of censored cases are listed separately in the KM table.
  • The value lists on EVENT or LOST 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 or LOST values must be enclosed in apostrophes, and the keyword THRU cannot be used.

Example

KM LENGTH BY SEXRACE
 /STATUS=EMPLOY  EVENT (1) LOST (3,5 THRU 8).
  • STATUS specifies that EMPLOY is the status variable.
  • A value of 1 for EMPLOY means that the event (employment) occurred for the case.
  • Values of 3 and 5 through 8 for EMPLOY mean that contact was lost with the case. The different values code different causes for the loss of contact.
  • The summary table in the output includes columns for number lost and percentage lost, as well as for number censored and percentage censored.