Race and ethnicity in medical research.

To the Editor—Racial and ethnic differences in health and disease are real. For example, in the field of neurology, intracranial stenoses are more common among the Chinese population, and multiple sclerosis is uncommon, when compared with whites from Europe and North America. Studying various subgroups is important to detect different patterns of disease and to obtain aetiological clues; race also has implications in monitoring access to public health and in analysing treatment outcomes. In two of the five original articles in the February issue of the Hong Kong Medical Journal, the descriptive label ‘Mongoloid race’ appeared as a term in the ‘key words’. The intention is to inform readers that the studies investigated a Chinese population and not, say, white Bostonians. Individuals belonging to the same race share a common biological inheritance, whereas members of an ethnic group are characterised by a distinctive history, culture, language, and sense of identity. It is, however, becoming clear that the relative environmental and genetic contributions to both these concepts are complex; it is also difficult to disentangle them from related problems such as poverty and poor housing.