Abstracts

It is well known that mortality is increased in patients with epilepsy compared to the background population. Overall standard mortality rates (SMR) range between 1.9 and 3.6. One obvious cause of this excess mortality in epileptics is the presence of CNS disease e.g. brain tumors associated with both epilepsy and excess mortality. However, other causes of death play an important role in the excess mortality in epilepsy, such as accidents, sudden unexpected death in epilepsy (SUDEP) and suicide. Suicide accounts for 5-7% of all deaths in persons with epilepsy as compared with only 1-2% in the general US population. However, most of the studies have been small with fewer than 25 cases, and have included patients from selected populations e.g. inpatients.
From an unselected cohort of people who committed suicide in Denmark during 1980-97 we obtained information from cases, and 20 population[ndash]based controls per suicide matched for age, sex and date of suicide (controls). Data was obtained from four Danish longitudinal registries: 1) The Cause of Death Registry, 2) The Danish Psychiatric Central Registry, 3) The Danish Integrated Database for Labor Market Research, and 4) the Danish Civil Registration System. Suicide cases and controls were matched with data from the Danish National Hospital Registry (Landspatientregisteret) to identify patients with a diagnosis of epilepsy. We included both inpatients (1980 [ndash] 1997) and outpatients (1995 [ndash] 1997) according to a Danish version of the International Classification of Diseases (ICD). From 1980 to 1994 we used the diagnosis epilepsy codes: 345 (ICD 8) and from 1995 to 1997 we used the diagnoses G40 and G41 (ICD 10).
Data was obtained from 21.169 persons who committed suicide (cases) and from 423,128 controls. Among the persons who committed suiciee, 492 (2.32%) had a diagnosis of epilepsy as compared with 3,140 (0.71%) among the controls. The odds-ratio for epilepsy in cases versus controls was 3.17 (95%, Confidence interval: 2.88 - 3.50, p [lt] 0.001).
The frequency of epilepsy in this unselected, nationwide cohort was similar to the frequencies of epilepsy reported in other general populations. We identified a significantly increased frequency of epilepsy among patients who committed suicide. These findings establish suicide as a contributing cause to the increased mortality in patients with epilepsy.
[Supported by: The Danish Epilepsy Society]