Matching MCBS and Medicare Data: The Best of Both Worlds
Eppig, Franklin J., Chulis, George S., Health Care Financing Review
The MCBS is an ongoing household panel survey of approximately 12,000 elderly and disabled persons eligible for Medicare benefits.(1) Field work for the MCBS began in September 1991. To date, five MCBS Access-to-Care Public Use Files (PUFs) -- 1991 through 1994 -- have been produced and made available to the public. The Access-to-Care PUFs link survey data on access to and satisfaction with health care, supplementary health insurance, and health and disability status, which are typically collected in the fall round each year, to Medicare billing data that cover the entire calendar year.
These PUFs have been used extensively to analyze a variety of issues, including: access to health care (Physician Payment Review Commission, 1996; Rosenbach, Adamache, and Khandker, 1995); satisfaction with health care (Adler, 1995); premium payments for supplementary health insurance (Chulis, Eppig, and Poisal, 1995); the relationship between supplementary health insurance and Medicare spending (Chulis et al., 1993); risk adjusting per capita payments to Medicare health maintenance organizations HMOs) (Gruenberg, Kaganova, and Hornbrook, 1996); examining favorable HMO selection (Rodgers and Smith, 1996); and the characteristics of users of home health services (Mauser and Miller, 1994).
There are, however, some significant analytic limitations to the MCBS Access-to-Care PUFs. One limitation relates to the population covered. The Access-to-Care files represent the "always enrolled," that is, elderly and disabled Medicare beneficiaries entitled to Medicare for the entire calendar year. This enrollment concept excludes persons who come on the Medicare rolls during the year. More significantly, it excludes most persons who died during the year. Persons in this group have medical expenses that are considerably higher on average than surviving beneficiaries Lubitz and Riley, 1993).
Another limitation of the Access-to-Care PUFs is that they do not contain survey-reported use of health services and costs. The files do include use and payments for Medicare covered services from Medicare billing records. However, Medicare covers less than one-half of total health care expenditures for the elderly (Waldo et al., 1989). Two of the more financially significant health care services not covered by Medicare, and therefore not included in the Access-to-Care files, are outpatient prescription drugs and long-term facility care.
The 1992 MCBS Cost and Use PUF is designed to create a more complete user file, one that uses an "ever enrolled" population concept and that includes all survey-reported use and costs. The "ever enrolled" population includes use and costs for all Medicare beneficiaries in the program for any part of 1992, including those who joined the program during the year and those who died during the year. The Cost and Use file also includes survey reports for services not included in Medicare central billing files, including prescription drugs, long-term facility care, and Medicare services provided by HMOs. In addition, for Medicare covered services, the completeness and accuracy of services used, payments made, and sources of payment has been improved by an extensive operation to match and reconcile survey reports and Medicare bills. This article describes the methods used and the results from the matching and reconciliation process used to create the 1992 MCBS Cost and Use file.
MATCHING SURVEY AND ADMINISTRATIVE REPORTS
There has been a continuing emphasis in government-sponsored research to find better ways to use government administrative records to verify and augment information reported on surveys (Okner, 1974; Jabine and Scheuren, 1984). The advantages of linking survey reports to administrative records include verifying the accuracy of survey reports, adding data that was not (or could not be) obtained in the survey, and reducing the reporting burden on respondents. …