Trends in epilepsy mortality in England and Wales and the United States, 1950-1994.

The aim of this study was to analyze time trends in epilepsy mortality in England and Wales and the United States between 1950 and 1994. The authors calculated age- and sex-specific epilepsy mortality rates for the nine quinquennia from 1950-1954 to 1990-1994. Mortality rates were modeled as a function of age, period of death, and cohort of birth by using Poisson regression techniques. From 1950 to 1994, there were more than 110,000 deaths from epilepsy in the two countries. The secular trends in mortality were similar for both sexes and in both countries. Among people younger than age 20 years, epilepsy mortality declined steeply after 1950. For young and middle-aged adults, the rate of decline was lower. In the geriatric population, mortality declined between 1950 and 1974 but then increased. The Poisson model showed pronounced birth cohort effects. In the United States, epilepsy mortality fell with each successive birth cohort after 1905. In England and Wales, there was a similar decline in birth cohort mortality after 1905 for women but not until after 1950 for men. The pronounced birth cohort effect supports explanations that focus on antenatal and developmental factors as the cause for the decline in epilepsy mortality in all but the oldest age groups between 1950 and 1994.