Rationale:
Epilepsy is associated with increased mortality compared with the general population. Here we describe demographic and clinical characteristics by all-cause mortality in a cohort of people with epilepsy seen in a large clinical outpatient practice over 30 years.
Methods:
This retrospective cohort study reviewed deaths in the patient population from a neurology/epileptology practice in South Carolina. Mortality data on individuals were obtained from the National Death Index through 2016. Individuals were described by age at epilepsy onset (0-18, 19-39, 40-64 and 65+), sex, race (White, Black, other and unknown), category of epilepsy (partial and generalized) and if noted, results of EEG (normal, abnormal, normal/abnormal, unknown). A subset of individuals had additional information on anti-epileptic medication use.
Results:
After excluding those determined to not have epilepsy and with missing age and death information, the cohort consisted of 2459 patients (48.3% female; 36.4% Black; 54.8% aged < 18 years) seen between 1974 and 2004. Of those, 306 (12.4%) had died by 2016. Male sex and older age at epilepsy onset were associated with increased risk of death as was having a history of partial seizures.
After adjustment for sex and age group, the odds of mortality increased for those with documented partial seizures (OR=1.41; 95% CI=1.06-1.89); the risk of death was higher in males (OR=1.43; 95% CI=1.12-1.84) and increased with increasing age at epilepsy onset. Compared with children diagnosed with epilepsy before age 18, the odds of mortality in adults aged 18-39 was 1.67 (95% CI=1.25-2.24), 40-64 was 3.65 (95% CI=2.58-5.18) and 65 and over was 4.37 (95% CI=2.78-6.88). In those with information on antiepileptic medication use, a history of ever taking Depakote or Dilantin was associated with mortality; however, after adjustment for age at epilepsy onset, these associations disappeared.
Conclusions:
In these data, having partial seizures was significantly associated with mortality even after adjustment for age at epilepsy onset and sex. Investigation of cause of death including sudden unexpected death in epilepsy (SUDEP) is also of interest and currently underway within the cohort. Future analyses will include other parameters such as socioeconomic factors (e.g., education, job) and presumed etiology. Further research into the association with seizure category and reasons for this finding are warranted.
Funding:
Epilepsy Services and Research, Inc.