Table 7 Examples of indistinct, interchangeable or confusing usage of race and ethnicity and ancestry compiled from our sample set

(1) ‘To minimize confounding by ethnic variation we restricted our study population to individuals of self-reported European descent’ (Amos et al. 2008)

Authors do not explain why or how ‘ethnic variation’ would confound results. The relationship between ‘ethnic variation’, ‘self-reported European descent’ and genetic background is not explicated. No term defined

(2) ‘All genetic association analyses were stratified by self- identified race (white vs. African American) to avoid spurious associations due to population stratification’ (Rasmussen-Torvik et al. 2009)

The relationship between ‘self-identified race’, and population stratification is not explicated. No term defined

(3) Research populations—Gullah, African American and European American—are referred to as being of African and European descent respectively in main article body, while in the supplementary text they are referred to as ‘races’ (Nath et al. 2008).

Use of differing terminology to refer to the same populations. ‘Race’ is not defined

(4) ‘The self-identified race/ethnicity information for these AGRE individuals is listed below’; however, the table is entitled ‘AGRE self-identified ancestry’ and lists’ American Indian/Alaskan Native; Asian; Black or African American; More Than One Race; Native Hawaiian or other Pacific Islander; Unknown; and White (Wang et al. 2009)

Interchangeable use of ancestry, and race and ethnicity. No term defined

(5) ‘All samples must have Caucasian ethnicity based on hierarchical clustering of AIMs genotypes, and all other samples were excluded’. ‘Ancestry’ only, used in main article body, ethnicity used only in supplementary text (Glessner et al. 2009)

Authors are referring to the inference of population ancestral identity using empirical genomic methods. However, how ‘ethnicity’ relates to genetic background is not explicated. Inappropriate use of ‘ethnicity’, rather than ancestry. Use of anachronistic ‘Caucasian’, rather than ‘European’ terminology. No term defined

(6) ‘Only subjects that self-reported as being of European ancestry were retained, regardless of their self-reported race’; Genetically inferred population identity referred to as ‘imputed race’ (Yeager et al. 2009)

Relationship between ‘self-reported ancestry’, ‘self-reported race’, and ‘imputed race’ not explicated. Inappropriate use of ‘race’ with respect to ‘imputed race’. No term defined

(7) ‘Distributions of racial ancestries were the same in cases and controls’ (Walsh et al. 2008)

Inappropriate use of ‘racial’ and ‘ancestry’ together. No term defined