The Kaplan-Meier estimator, also known as product limit estimator, is used to estimate the survival function from lifetime data. It is often used to measure the fraction of study subjects that are still alive after a certain amount of time after treatment. The curve obtained from the Kaplan-Meier estimator takes right-censoring data into account so that subjects withdrawing from the study prematurely or finish the study without event occurrence can be dealt with accordingly.
The data passed to this node is a table with one row for each study subject. For each subject the event that is studied either occurred, so that the event column contains a boolean True value, or the subject left the study (boolean False). Additionally to this information the time the event or censoring has taken place must be present. More information about the Kaplan-Meier estimator can be found on Wikipedia .