Use of race, ethnicity, and ancestry data in health research

Abstract

Race, ethnicity, and ancestry are common classification variables used in health research. However, there has been no formal agreement on the definitions of these terms, resulting in misuse, confusion, and a lack of clarity surrounding these concepts for researchers and their readers. This article examines past and current understandings of race, ethnicity, and ancestry in research, identifies the distinctions between these terms, examines the reliability of these terms, and provides researchers with guidance on how to use these terms. Although race, ethnicity, and ancestry are often treated synonymously, they should be considered as distinct terms in the context of health research. Researchers should carefully consider which term is most appropriate for their study, define and use the terms consistently, and consider how their classification may be used in future research by others. The classification should be self-reported rather than assigned by an observer wherever possible.

Fig 1. Variation involving 0.1% of the human genome.

(A) Proportion of human genome sequence that is similar (blue) and varies (orange) across individuals. (B) A close examination of the DNA sequence (between positions 11 and 17 included) of gene A reveals 2 genetic variants: Variant #1 (position 1012 on chromosome): All participants from Ancestry 1 have a T allele, while participants of ancestry 2 have both T and A allele. This variant could be ethnic specific and could potentially be used as an ancestry marker; Variant #2, (position 1017): the two alleles G and C are observable in both ancestry groups with similar frequencies, hence, this genetic variant is not an ancestry informative.

Fig 2. Validation and imputation of self-reported ethnicity using genetic data.

Fig 3. Race, ethnicity, and ancestry considerations in health research.