Mortality following status epilepticus in persons with and without epilepsy

Incidence of status epilepticus (SE) ranges from 6.8 to 41.0 per 100,000 population. Although SE is associated with significant morbidity and mortality, the temporal relationship between SE, epilepsy, and mortality is less clear. The risk of all-cause mortality following SE with and without prior epilepsy was investigated.

This study identified hospitalizations and emergency department visits for persons with SE and persons with epilepsy between 2000 and 2013. Excluded were those with epilepsy subsequent to SE, epilepsia partialis continua, less than 90days follow-up, and less than 2 years of data prior to first diagnosis. The cohort was grouped into: 1) SE only, 2) post-epilepsy SE (PES), and 3) epilepsy only. The risk of mortality was estimated using Cox proportional hazard models adjusting for potential confounders.

The cohort (N=82,331) consisted of 1296 SE only cases (1.6%); 2136 PES cases (2.6%); and 78,899 epilepsy only controls (95.8%) with 24.9%, 29.2% and 20.0% mortality, respectively. Compared with controls, the hazard of mortality was increased for those with SE only (hazard ratio [HR]=1.61, 95% CI=1.41-1.82) and PES (HR=1.16, 95% CI=1.07-1.25) after adjustment for demographic and clinical factors. Prior stroke, central nervous system infection, and brain tumor increased the mortality hazard.

There is a statistically significant increased risk of all-cause mortality with SE. The risk is stronger in those with no prior epilepsy. Specific etiologies increase mortality risk in those with SE warranting further investigation of the complex associations between these etiologies and SE.