Ethnic minority groups must be included in European health research

Despite the knowledge that ethnicity matters in cardiovascular disease, most studies of cardiovascular disease risk have not been designed to yield results that apply to different ethnic groups, report Meghna Ranganathan and Raj Bhopal (of Edinburgh University) in a new study in the international open-access medical journal PLoS Medicine.

To ensure that the results of research studies can be applied to everyone in a multicultural society, it is important that all racial and ethnic groups are included in health research. This need is especially obvious for studies of diseases for which it is known that different risk factors exist in different parts of the population. Cardiovascular disease, the number one killer in most developed countries, is one of them. The disease, which is the underlying cause for heart attacks, strokes, and other serious health threats, is a major cause of death for all ethnic groups, and the risk is especially high in individuals originating from South Asia. In the UK for example, early deaths from coronary heart disease in Indians, Bangladeshis, Pakistanis, and Sri Lankans are about 50% higher than the national average. For Caribbeans and West Africans, on the other hand, the rates are much lower than average.

To examine whether ethnicity was taken into account in cardiovascular disease research, Ranganathan and Bhopal conducted a systematic review of the medical literature. They analyzed in detail 72 large studies that examined cardiovascular disease risk in European and North-American populations.

The results highlight a disconnect between the world of research and the "real world" of increasingly diverse societies: most of the studies did not provide detailed information on the ethnic composition of the broader populations from which the participants were recruited, nor did they state whether minority groups were included or excluded from the study. Many of them did not give details on the ethnic composition of the participants themselves, or on how the participants’ ethnicity was determined. Studies with participants that were representative of diverse populations usually were not large enough to answer the kind of questions necessary to determine differences between different ethnic groups.

However, among the more recent studies, ten were designed to specifically compare white and non-white participants, and five studies focused on non-white minority groups specifically. All fifteen of those studies were done in the US. As the authors conclude, “urgent action is needed in Europe” to ensure that research studies reflect the increasingly multicultural nature of the societies there, and are thus relevant to all of parts of those societies.