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)
