The Validity of Race and Ethnicity in Enrollment Data for Medicare Beneficiaries


Address correspondence to Alan M. Zaslavsky, Ph.D., Department of Health Care Policy, Harvard Medical School, 180 Longwood Avenue, Boston, MA 02115; e-mail:



To assess the validity of race/ethnicity in Medicare databases for studies of racial/ethnic disparities.

Data Sources

The 2010 Medicare Consumer Assessments of Healthcare Providers and Systems (CAHPS®) survey was linked to Medicare enrollment data and local area characteristics from the 2000 Census.

Study Design

Race/ethnicity was cross-tabulated for CAHPS and Medicare data. Within each self-reported category, demographic, geographic, health, and health care variables were compared between those that were and were not similarly identified in Medicare data.

Data Collection Methods

The Medicare CAHPS survey included 343,658 responses from elderly participants (60 percent response rate). Data were weighted for sampling and nonresponse to be representative of the national population of elderly Medicare beneficiaries.

Principal Findings

Self-reported Hispanics, Asians, Pacific Islanders, and American Indians were underidentified in Medicare enrollment data. Individuals in these groups who were identified in Medicare data tended to be more strongly identified with their group, poorer, and in worse health and to report worse health care experiences than those who were not so identified.


Self-reported members of racial and ethnic groups other than Whites and Blacks who are identified in Medicare data differ substantially from those who are not so identified. These differences should be considered in assessments of disparities in health and health care among Medicare beneficiaries.