Cause-specific mortality in epilepsy: a cohort study of more than 9,000 patients once hospitalized for epilepsy.

PURPOSE: We studied overall and cause-specific mortality rates in a large cohort of patients with epilepsy compared with mortality rates of the general population in the same geographic area.

METHODS

The cohort consisted of all patients (N = 9,061) aged > 15 years admitted with a diagnosis of epilepsy for inpatient care in Stockholm during the years 1980-1989. All patients were followed in the National Cause-of-Death Register, from which the causes of death were obtained, until December 31, 1992. Thus, 53,520 person-years were observed. Mortality rates were compared with those of the general population of Stockholm.

RESULTS

We observed 4,001 deaths in the cohort, compared with an expected number of 1,109 deaths in the general population. This yielded a standardized mortality ratio (SMR) of 3.6 [95% confidence interval (CI) 3.5-3.7]. Although highest in the younger patients, the SMR was significantly increased in all age groups. The excess mortality rate in the cohort was due to a wide range of causes of death, including malignant neoplasms [SMR 2.6 (2.4-2.8)], diseases of the circulatory system, [SMR 3.1 (3.0-3.3)], diseases of the respiratory system [SMR 4.0 (3.6-4.5)], diseases of the digestive system [SMR 5.1 (4.4-5.8)], and injuries and poisoning [SMR 5.6 (5.0-6.3)].

CONCLUSIONS

Our results demonstrate that this large subgroup of patients with a diagnosis of epilepsy, once hospitalized and discharged, is a population at risk, with an excess mortality rate due to several different causes.