The Surv-Date Active Followup is defined as the earlier of the Date of Last Contact [1750] and a study cutoff date. The study cut-off date is a pre-determined date based on the year of data submission and is set in the survival program used to derive the seven survival variables. If the Date of Last Contact [1750] is earlier than the study cut-off date and either the day or month is unknown or not available, the values are imputed by the survival program. The survival program is available from your standard setter or NAACCR.

Example 1

Date of Last Contact: 20111120

Study Cut-off Date: 20111231

Surv-Date Active Followup: 20111120

Note: The date of last contact is earlier than the study cut-off date, and the date of last contact is complete, so the date of last contact is used in Surv-Date Active Followup.

Example 2

Date of Last Contact: 201111

Study Cut-off Date: 20111231

Surv-Date Active Followup: 20111115

Note: Rationale is to take mid-point of possible values. For Nov (30 days) it would be FLOOR((1+30)/2) = 15, where FLOOR is a function that rounds a decimal down to an integer.

The Surv-Date Active Followup is needed to be able to recalculate survival months if a different study cut-off date is used and provides flexibility to recalculate survival without needing to rerun the survival program on the original data.

Additional information about the survival algorithm and what specific values are assigned in given missing date situations are available here: <http://seer.cancer.gov/survivaltime/>.

If Date of Last Contact [1750] is blank, Surv-Date Active Followup will also be blank.