Linking Data on Dual Eligibles to Improve Services

Medicare beneficiaries who are also eligible for Medicaid are a vulnerable population because of their disproportionately high medical and long-term care needs and their low incomes. Known as dual eligibles, about 11 percent of older Americans covered by Medicare fall into this category. A much higher proportion—nearly 40 percent—of disabled Medicare beneficiaries are dual eligibles. While Medicare covers major medical expenses, co-pays and deductibles are often unaffordable for this group. Medicaid fills in the gaps by offering health and long-term care coverage, including prescription drugs. Many dual eligibles suffer from chronic illnesses, have multiple health problems, and have relatively high Medicare expenditures, so they have been of great importance to policymakers. 

Detailed information on coverage for dual eligibles has been fragmentary and often not comparable across states. To help policymakers better understand dual eligibles, Mathematica designed and developed a research-quality database on this population in California, Colorado, Florida, Georgia, Indiana, Iowa, Kentucky, Maine, Michigan, New Jersey, Washington, and Wisconsin. The linked database contains Medicare and Medicaid files, along with supplemental state data to summarize enrollment utilization and expenditures for dual eligibles from 1994 to 1996. The database, which is larger and more detailed than any other database previously assembled on dual eligibles, is a rich source of information on this at-risk population.

To date, researchers have used the database to report on risk adjustment for dual eligibles in managed care, to provide descriptive statistics on dual eligibles in nine states, and to examine the use of Medicaid pharmacy benefits. Two additional studies on the following topics are underway:

• Medicare and Medicaid coverage of home health care for dual eligibles
• Medicare and Medicaid expenditures for dual eligibles in nursing homes

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