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National Cancer Data Base - Data Dictionary PUF 2015

Reference Date Flag

DD_category: 
PUF Data Item Name: 
REFERENCE_DATE_FLAG
length: 
1
Allowable values: 
0, 1
Description: 
Identifies whether a report for a case has a diagnosis date before or after the facility's reference date.
NCDB System Code Assignments: 

0 = Diagnosis date before reference date
1 = Diagnosis date on or after reference date

Analytic Note: 

Every facility has a reference date, from which they are accountable for the completeness of the data for cases diagnosed in that year through the present. Since a facility may request to move their reference date forward, there are some instances where a case’s diagnosis year falls before the facility’s reference date. This item is coded 0 in cases where this occurs. A 1 signifies cases where the diagnosis year is on or after the reference date year. Reports for cases whose diagnosis date is prior to the reference date cannot be changed or updated by the facility. For this reason, PUF researchers may choose to omit cases where the diagnosis date precedes the reference date, depending on the nature of the study.