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.