Linking Medicare, Medicaid, and cancer registry data to study the burden of cancers in West Virginia.

OBJECTIVE Develop the WVCR-Linked dataset by combining the West Virginia Cancer Registry (WVCR) with Medicare, Medicaid, and other data sources. Determine health care utilization, costs, and overall burden of four major cancers among the elderly in a rural and medically underserved state population, and to compare them with national estimates. METHOD We extracted personal identifiers from the West Virginia Cancer Registry (WVCR) data file for individuals ≥ 65 years of age with an incident diagnosis of any cancer between January 1, 2002 and December 31, 2007. We linked the extracted data with Medicare and Medicaid administrative data using deterministic record linkage procedures. We updated missing vital status information by linking the National Death Index (NDI) data file. The updated WVCR-Linked dataset was enriched by links to the U.S. decennial census (2000) file and the Area Resource File. RESULTS We identified 42,333 individuals, of which 41,574 (98.2%) and 6,031 (14.3%) individuals were matched with Medicare and Medicaid administrative data files, respectively. The NDI data added or updated vital status information for 3,295 (7.8%) individuals in the WVCR-Linked dataset. CONCLUSION The WVCR-Linked dataset is a comprehensive dataset offering many opportunities to understand factors related to cancer treatment patterns, costs, and outcomes in a rural and medically underserved elderly Appalachian population. Following our example, non-participant states in the Surveillance, Epidemiology and End Results (SEER) program can build a powerful dataset to identify and target cancer disparities, and to improve cancer-related outcomes for their elderly and dual-eligible citizens.