symptom level in Indian immigrants to England (unspecified date before 1981)
Using 1971 census data, Indian immigrants were chosen from four areas with a high density of this ethnic group: Slough, London, Birmingham, and Coventry. The study excluded ethnic Indians from East Africa. All Indian subjects were born in India; this was the sole criterion for the de®nition of the group. The comparison group of native-born English was also de®ned solely by place of birth. The Indian sample was selected using a random walk technique. The indigenous sample was obtained from comparable working-class residential areas of other large towns.