Mortality patterns and the effect of socioeconomic factors on mortality in rural Tamil Nadu, south India: a community-based cohort study.

The importance of mortality data for assessing the health status of any population and for planning disease control and health promotional interventions is well established. A population-based cohort study was conducted in Kaniyambadi Block, a rural block in North Arcot District in Tamil Nadu, India, with a population of approximately 120,000 people living in 88 villages. The mortality rates, patterns and effect of socioeconomic factors on mortality were studied. The overall incidence of mortality in the study cohort was 7.3/1000 person-years, with higher rates of mortality among men than women. People with low socioeconomic status (SES) had almost two-fold higher mortality rates across all age groups compared with people with high SES. Deaths due to injuries and other external causes contributed 23.0% of all deaths, among which the low socioeconomic group had 56% excess cause-specific mortality compared with the high socioeconomic group. Standardised mortality ratios indicated that the low socioeconomic group had 25% excess mortality compared with the overall standard mortality. This study clearly shows that the low SES group had a significantly higher incidence of mortality due to all causes and among all age groups.