The study of mortality variations in small administrative areas of England and Wales, with special reference to cancer.

Until recently the basic geographical unit in England and Wales for the compilation of population and mortality data has been the local authority administrative district. Epidemiologists have made little use of the mortality data available from 1950 for small administrative districts: municipal boroughs, urban and rural districts. In April 1974 the boundaries of administrative areas were radically revised, but mortality data for the old districts were still compiled up to 1978. In this paper we review the material available for small districts and its uses and limitations for research into the causes of cancer. It is argued that these data covering 29 years deserve to be more widely used both for generating clues and for testing hypotheses about the aetiology of cancer and other chronic diseases.