What is the incidence of SUDEP?

SUDEP is estimated to account for up to 18% of all deaths in patients with epilepsy.

Consistent, and comparable, data on the incidence of SUDEP and its risk factors is proving difficult to ascertain.  This is due to differences in research methodologies (including, definition of SUDEP, study type and reference populations) and inevitable methodological limitations.  Most studies are restricted to smaller sample sizes and select epilepsy groups (such as tertiary care clinics or residential homes) because of the relatively rare incidence of SUDEP in the population and the impracticality of studying large numbers of individuals with epilepsy from diagnosis to death.

The alternative research approach, conducting retrospective studies of those identified as having died from SUDEP, is hampered by the apparent underuse of the term SUDEP as a cause of death on death certificates, as found in the UK (
Langan et al 2002) and the USA (Schraeder et al 2006).  Instead, the cause may be registered as, for example, ‘respiratory failure’ or ‘unascertained’ and would thereby be erroneously excluded from SUDEP case studies or statistics.

Epidemiological data from research conducted to date has demonstrated substantial variance in incidence depending on the epilepsy cohort studied.  This has been shown to range from 0.09 per 1000 person-years in a community-based study (
Lhatoo et al 2001) to 9 per 1000 person-years in candidates for epilepsy surgery (Dasheiff 1991).

Next: Minimising the risk of SUDEP