Epilepsy mortality and risk factors for death in epilepsy: a population-based study

Epilepsy is an important cause of amenable mortality but risk factors for death in epilepsy are not well understood.

To evaluate trends in epilepsy mortality in a large population and identify risk factors for death in epilepsy.

Nested case-control study in the UK, using data from the General Practice Research Database (GPRD) from 1993 to 2007.

Participants were included if they had ever been diagnosed with epilepsy and prescribed anticonvulsant drugs. Trends in all-cause mortality in persons with epilepsy in the GPRD were compared with death registrations with epilepsy as the underlying cause. A nested case-control study was implemented to compare participants with epilepsy who died with those who did not die.

The prevalence of epilepsy increased from 9 per 1000 in 1993 to 12 per 1000 in 2007, and epilepsy deaths also increased in this period. In a nested case-control study, mortality was associated with: recorded alcohol problems (odds ratio [OR] 2.96, 95% confidence interval [CI] = 2.25 to 3.89, P<0.001); having collected the last anticonvulsant prescription 90-182 days previously (OR 1.83, CI = 1.66 to 2.03, P<0.001); having an injury in the previous year (OR 1.41, 95% CI = 1.30 to 1.53, P<0.001), and having been treated for depression (OR 1.39, 95% CI = 1.28 to 1.50, P<0.001). In data available from 2004 onwards, being recorded seizure free in the previous 12 months was associated with lower mortality (OR 0.78, 95% CI = 0.71 to 0.86, P<0.001).

Mortality with epilepsy appears to be increasing. Patients who have alcohol problems, do not collect repeat prescriptions for anticonvulsant drugs, have recent injuries, or have been treated for depression may be at increased risk of death; patients who remain seizure free over 12 months are at a lower risk.