Incidence and risk factors of sudden unexpected death in epilepsy in rural Northeast China

Purpose

This prospective cohort study aims to provide detailed data on the incidence and risk factors of sudden unexpected death in epilepsy (SUDEP).

Methods

We recruited 6,513 patients with convulsive epilepsy from rural areas of Northeast China for regular follow-ups. Mortality cases, including probable and suspected SUDEP, were identified through death certificates, verbal autopsies, and expert panel discussions. We calculated overall, sex-adjusted, and age-specific SUDEP incidence rates, along with cumulative incidence under competing risks. We employed univariate Cox regression analysis and multivariable competing risks regression analysis to identify potential risk factors associated with SUDEP.

Results

The overall SUDEP incidence was 1.46 per 1,000 person-years, with rates of 1.50 for females and 1.42 for males. The cumulative incidence of SUDEP at 1, 3, and 5 years was 0, 1.09‰, and 1.95‰, respectively. SUDEP incidence peaked in individuals aged 30–49 years. Body mass index, age at onset, and recent high-frequency generalized tonic-clonic seizures significantly increased SUDEP risk, with high-frequency seizures being the strongest predictor. Epilepsy duration, consciousness status during seizures, and anti-seizure medication count were not linked to SUDEP. Improved medication adherence, though not directly reducing SUDEP risk, could lower seizure frequency, thus indirectly decreasing SUDEP risk.

Conclusion

High-frequency seizures, younger age at onset, and overweight status significantly increased the risk of SUDEP in patients with convulsive epilepsy. These findings contribute to the development of a SUDEP risk profile, facilitating the precise identification of high-risk individuals and informing prevention and management strategies.