Mortality in patients with epilepsy: 40 years of follow up in a Dutch cohort study

To investigate the extent of and the causes of excess mortality in patients with epilepsy, mortality was studied in a cohort of patients with newly diagnosed epilepsy over an extended follow up period. All patients (both inpatients and outpatients) of the Instituut voor Epilepsiebestrijding in Heemstede, the Netherlands between 1953 and 1967 were included in the study. Complete follow up was obtained for 1355 patients, 746 men and 609 women. The mean follow up was 28 years (range 6 months-41 years). In total, 38 665 person years were surveyed, in which 404 patients died. All cause mortality was threefold increased (risk ratio (RR) 3.2; 95%CI 2.9-3. 5), and was only slightly higher for men than for women. Mortality was highest under 20 years of age (RR 7.6; 95%CI 6.5-8.7), and during the first 2 years of follow up (RR 16; 95%CI 12-20). Mortality directly related to epilepsy accounted for 18 of the 53 deaths in the first 2 years after diagnosis, which is equivalent to an incidence rate of 6.8 per 1000 person-years (95% CI 4.1-10). After 2 years 110 of the 351 deaths could be attributed to epilepsy itself, or were epilepsy related, with an incidence rate of 3.1 per 1000 person-years (95% CI 2.5-3.6). The data presented suggest that the increased mortality risk in patients with epilepsy is attributable in part to epilepsy itself, and is predominantly present at younger age and early after diagnosis. However, the absolute risk is moderate.