Social disparities and cause-specific mortality during economic development

Social patterning of disease is pervasive and persistent. Disease patterns change with economic development and the attendant epidemiological transition. It is becoming evident that social patterns of disease are epidemiologically stage specific. In a population with a recent history of rapid economic development we examined social patterns of all-cause and cause-specific mortality over time to elucidate how economic development impacts disparities in health. We used concentration indices to provide a summary measure of disparities by income in potential years of life lost (PYLL) for the Hong Kong population from 1976 to 2006. For all-cause mortality and for each of the specific causes considered the concentration curve in 2006 dominated the 1976 concentration curve. The concentration index for all-cause PYLL was negligible in 1976, but increased over the period. PYLL attributable to injury and poisoning was fairly consistently associated with lower income, but PYLL attributable to cardiovascular diseases and cancer reversed from an association with higher income in 1976 to an association with lower income in 2006. Social disparities in health are not universal or homogeneous in origin. Attention should be focused on disease-specific causes of disparities, so that contextually specific prevention strategies can be implemented. This is of particular relevance to China and other emerging economies where there may be a window of opportunity to prevent disparities in cancer and cardiovascular diseases occurring.