Epidemiological study of mortality in epilepsy in a Spanish population

PURPOSE Studies concerning mortality in epilepsy have been performed primarily in Northern-Central Europe and US. The aim of this study was to provide information about mortality in people with epilepsy in Southern European countries. METHOD We studied a Spanish prevalence and incidence cohort of 2309 patients aged ≥14 years with epilepsy who were treated in an outpatient epilepsy clinic between 2000 and 2013. The deceased were identified through Civil Registries. Causes of death were determined using death certificates, forensic autopsies, hospital reports, family practitioners, and care-givers' records. Standardised mortality ratios (SMRs) were calculated. RESULTS In a total of 15,865 person-years of follow-up, 152 patients died, resulting in an SMR of 2.11 (95% CI 1.79-2.47), which was higher for those aged 14-24. There was also a high rate of death for symptomatic epilepsies, progressive causes (SMR=6.12, CI 3.50-9.94), and remote causes (SMR=2.62, CI 2.12-3.21). High SMRs were found for all kinds of epilepsy and for respiratory and tumoural causes. Patients who died of epilepsy itself were 12.5%. Sudden unexpected death in epilepsy incidence was 0.44:1000. Death from status epilepticus incidence was 20:100,000. SMRs for external causes were of no statistical significance. CONCLUSIONS This is the first epidemiological study to examine rate of mortality in epilepsy in a Southern European country. The identified mortality pattern is similar to the one provided by researchers from developed countries. The similarities between our results concerning epilepsy-related deaths and those provided by population-based studies are the result of the scarcely selected character of our study cohort.