Reporting of ethnicity in research on chronic disease: update.

This paper examines the inclusion of ethnicity and race as variables in current, leading edge research on chronic disease and its risk factors. Of 100 randomly selected original research articles published in high-impact journals in 2005, 85% did not report either a definition of ethnicity or its conceptualisation in terms of theoretical reasoning, and 98% did not report an actual measurement item. Ethnicity and race remain non-standardised and largely underdescribed variables in research on chronic disease. This represents an important loss of opportunity to articulate and test hypotheses about the mechanisms underlying ethnic group differences in chronic disease.