The epidemiology of status epilepticus in the United States.

OBJECTIVE: To summarize trends in status epilepticus (SE) in the United States by age, race, sex, admission source, disposition, incidence rates, and mortality.

METHODS: Data from US National Hospital Discharge Survey were used from 1979 to 2010 to identify discharges with SE and common etiologies and complications of SE using International Classification of Diseases, 9th Revision, Clinical Modifications codes. Temporal trends in the incidence and in-hospital mortality of SE were examined with respect to age, sex, and race.

RESULTS: We identified 760,117 discharges with SE over 32 years. The incidence of SE increased from 3.5 to 12.5/100,000 between 1979 and 2010, without a significant change in in-hospital mortality. Higher incidence, earlier age of onset, and higher mortality were observed among males. Age stratification revealed a "U-shaped" distribution with higher incidence at age <10 years (14.3/100,000) and age >50 years (approaching 28.4/100,000). In-hospital mortality, however, was the lowest (2.6 %) at age <10 years and approached 20.2 % with age ≥80 years. The incidence of SE was higher among blacks (13.7/100,000), compared to whites (6.9/100,000) and other races (7.4/100,000). Mortality, however, was lower among blacks (7.2 %) compared to whites and other races (9.8 and 9.2 %, respectively). Black men had the highest incidence (15.0/100,000), relatively younger age of onset (39.3 years) and the lowest mortality (5.6 %). A net temporal decline in the reported prevalence of epilepsy, central nervous system infections, and traumatic brain injury was noted among SE cohort.

CONCLUSIONS: The incidence of SE increased nearly fourfold with relatively unchanged mortality. Gender and racial disparities exist in the incidence of SE, and age is an important predictor of mortality.