Why we need to create standardized Medicaid administrative data linked with cancer registry databases
I read with interest the two articles1,2 published in the Winter 2008 issue of the Journal of Registry Management that report analysis based on linking cancer registry data with administrative or medical claims data. Both these articles limit their analysis to those aged 65 years and older, the age group that appears to be the focus of the majority of the research using similar linked databases. There have been a limited number of studies3–5 using linked databases for those younger than 65 years, but these studies reflect a very small pool of evidence compared to the over 300 scientific articles that have been produced using the linked Surveillance, Epidemiology and End Results (SEER)-Medicare database alone for the elderly age groups.
Overall, about 45% of all cancers are diagnosed among those younger than 65 years and this age group has a higher incidence of certain types of cancers, including breast and skin cancer.7 The incidence rates therefore do not justify the skewed focus on the elderly in the analysis performed using linked cancer registry/administrative databases. There are several potential explanations for this. First, the health insurance coverage for the population younger than 65 years is fragmented; many are covered by private health plans sponsored by employers, others are enrolled in Medicaid, and a large number are uninsured. Second, individual state programs and private health plans often do not have large enough cohorts of cancer patients and therefore studies need to pool data from multiple sources to perform the required analysis. Third, no standardized linked dataset such as the SEER-Medicare database is available for the younger population.