The Southall Diabetes Survey: prevalence of known diabetes in Asians and Europeans.

A house to house inquiry for patients with known diabetes was carried out in a defined area of Southall, west London, which contained over 34 000 Asians and 27 000 Europeans in the 1981 Census: 1143 diabetic patients were ascertained, of whom 761 were Asian and 324 European. The prevalence adjusted for age of known diabetes in Asians was at least 3.8 times higher than that in Europeans. For patients aged between 40 and 64 years it was at least five times higher, was over 12% in Asians aged 60-69, and over 8% in those aged 50-59. These data are important in planning for the care of diabetic patients in health districts with large Asian communities. The causes and later consequences of this exceptionally high prevalence require further study.