Ethnicity and cardiovascular health research: pushing the boundaries by including comparison populations in the countries of origin.

Chronic diseases such as cardiovascular diseases (CVD) are major health problems in most ethnic minority and migrant populations living in high income countries. By the same token, CVD is a looming threat that is creating a double burden in most of the countries where these populations originate from. The causes of the rising burden are unclear, but they are likely to be multifaceted. Traditionally, ethnicity and health research have mostly concentrated on comparing the health of ethnic minority groups with the majority populations of the countries in which they live. This is an important area of research which illuminates ethnic inequalities in health. However, a few studies on international comparisons show that a lot can be learned from comparing similar ethnic groups living in different industrialised countries. Equally, comparing ethnic minority and migrant populations to similar populations in their countries of origin will generate new knowledge about factors that predispose them to poor health outcomes. Thus, to make progress in the field of ethnicity and health research, we need a new conceptual framework that simultaneously studies migrant/ethnic groups in the country of settlement, in similar countries of settlement, and in the countries of ancestral origin. Such studies need to go beyond the commonest design of cross-sectional studies to include more cohort studies, interventions and linkage studies. This article discusses (1) the burden of CVD in ethnic minority and migrant populations; (2) approaches to understanding predisposing factors; and (3) application of the results to give insight into the potential threats that their countries of origin are likely to face.