One central cancer registry’s use of National Death Index (NDI) linkage to become a survival registry

BACKGROUND: The Missouri Cancer Registry and Research Center (MCR-ARC), like many population-based central cancer registries (CCRs), is an incidence-only registry since it lacks complete survival information. In order to measure the impact of public health and other programs aimed at improving population health, MCR-ARC needs to become a survival registry – one with complete survival information. NDI is an index of all states’ death records. The NDI linkage, the final part of a multi-step process, begins with review of a state’s own vital statistics death file and includes Social Security Death Index (SSDI) linkage. MCR has recently embarked on the first step to become a survival registry by focusing on patients with breast and cervical tumors.

PURPOSE: Describe processes associated with conducting NDI linkage.

METHODS: After conducting annual death clearance and follow-back for all cancer cases diagnosed in 2011, we conducted SSDI linkage on breast and cervical cancer cases diagnosed 1996 through 2011 to reduce the number of cases with unknown vital status or Social Security Number, and then performed an NDI linkage for all the remaining breast and cervical cancer cases marked alive or dead with unknown cause. Staff reviewed linkage results to identify matches, then updated the database to include the date and cause of death.

RESULTS: We obtained death data for patients who were Missouri residents at the time of their diagnosis and had incomplete survival information. After completing review of matches and potential matches, we updated the database. Results will be presented.

DISCUSSION/CONCLUSIONS: The process for the NDI linkage differed significantly from the process that the registry uses for other linkages, but utilizing tools produced for the CDC’s National Program of Cancer Registries, the burden was reduced substantially. NDI linkage provides a cost-effective method of obtaining information needed by researchers evaluating programs, analyzing treatment outcomes, etc.