Participation in clinical research among racial and ethnic minority Medicare beneficiaries: Evidence from the IDEAS...

Racial and ethnic disparities in clinical research, although documented in aggregate, are poorly understood due to a lack of data on the population eligible to participate. We compared the characteristics of Medicare beneficiaries who participated in the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) study to those eligible to participate.

We used 100% Medicare claims data from 2016 to 2017 to identify IDEAS study participants and those eligible to participate.

We identified 11,480 beneficiaries in the IDEAS study sample and 3,008,067 in the eligible sample. Participants were more likely to reside in urban areas, less likely to be enrolled in both Medicare and Medicaid, or a Medicare Advantage plan. Black and Hispanic participants were more likely to reside in higher-income counties and were healthier than the eligible sample.

Racial and ethnic minority participants in clinical research differ from those eligible, particularly in socioeconomic and insurance characteristics, affecting generalizability.

In this study, we compared the characteristics of Medicare beneficiaries participating in the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) study and Medicare beneficiaries eligible to participate in the IDEAS study. We use 100% claims of Medicare beneficiaries. Hispanic and Black beneficiaries in the IDEAS study participant sample were more likely to reside in an urban area, less likely to be dually enrolled in Medicare and Medicaid, and more likely to reside in a county with higher income compared to the Hispanic and Black beneficiaries IDEAS eligible sample. Across racial/ethnic groups, IDEAS study participants were more likely to be enrolled in Traditional Medicare compared to the IDEAS eligible sample.