Survival Analysis Variables

Description

Use a calculated variable to return the count of days between the baseline date and the date of an event of interest.

How To

Note: Survival analyses require two variables: 1) whether or not it is a "Censored" event, and 2) the length of time to the event of interest.

Censored Event:

Select the event date (e.g., death) and use the following function:

function main(deathDate) {

  if (isNull(deathDate)) {

    return 0;

  }

  return 1;

}

Length of Time to Event:

Select the event date (e.g., death), baseline date and the last available encounter date (all encounter dates are needed, unless using an "Output Interval" containing the baseline and last follow-up).

function getLength() {

if isNull(baselineDate) {

   return null;

} else if (!isNull(deathDate) {

   return days between Baseline and Death;

} else if (longestEncounterDate) {

   return days between Baseline and longestEncounterDate;

} else if (SecondLongestEncounterDate) {

   return days between Baseline and SecondLongestEncounterDate;

} etc.....

}

Note the image below uses VBScript, but above code uses JavaScript (recommended)