Use the Parameters tab in a Survival session to specify the dates, intervals, and vital status involved with the calculation of survival time, as well as whether and how to display the Standard Life Tables, Cumulative Summary, and/or Z-test pages.
The date, interval, and vital status parameters establish how case survival time will be defined and the intervals that will be used in the analysis.
The survival time for each case is calculated and then partitioned into the defined survival duration intervals. For every life table, SEER*Stat calculates the number of cases alive at the beginning of each survival interval. A case is counted as entering the first interval alive, and either survives into the next interval, or its survival time terminates somewhere within the current interval. If the case does not survive into the next interval, it is either counted as dying during the current interval, or its vital status indicates that it is alive, but does not have enough survival time to go into the next interval. In the latter case, it is counted as lost to follow-up or withdrawn during the interval, depending on the relationship between the End Date of Calculation and the Lost to Follow-up Date.
Cases that are alive and have identical begin and end dates of calculation are deleted from the analysis since the survival time is zero. The number of cases for which survival could not be calculated is included in the Information section of the Matrix Properties.