Epidemiology of epilepsy and its burden in Kolkata, India

BackgroundDisability-adjusted life year (DALY) is a time-based measure of disease burden incorporating both disability and mortality. Our study aimed to determine the DALY lost from epilepsy in an Indian metropolis. MethodsA population-based prospective study on epilepsy was conducted over 5years (2003-8) in Kolkata, India, on randomly selected 100,802 subjects (males 53,209, females 47,593) to assess prevalence as well as to capture incident cases of epilepsy and those incident cases that died. Standard case definitions were used. The data were used to estimate years of life lost (YLL) due to premature mortality, years of life lived with disability (YLD), and DALY, utilizing the prevalence-based Global Burden of Disease (GBD) 2010 approach. Age- and gender-specific figures were computed. ResultsDuring 2003-2004, a total of 476 subjects with active epilepsy were detected and the age-adjusted prevalence rate was 4.71 per 1000. Over 5years, there were 197 incident cases of epilepsy of whom 26 died. The age-adjusted annual incidence rate of epilepsy was 38.3 per 100,000. The all-cause standardized mortality rate (SMR) of epilepsy was 2.4. The burden of epilepsy in the year 2007-8 revealed the overall YLL was 755 per 100,000, and the overall YLD ranged from 14.45 to 31.0 per 100,000 persons depending on the clinical severity of the epilepsy. Both YLL and YLD values were higher in males than in females. The overall DALY lost due to epilepsy in 2007-8 was found to be 846.96 (males 1183.04, females 463.81) per 100,000. ConclusionsThis is the first study in India to determine the DALY of epilepsy using GBD 2010. The results reveal a substantial burden of epilepsy in our setting. Similar such studies are needed in other parts of India in both urban and rural settings.