Epilepsy Mortality Study: Findings From Two First Seizure Clinics

What was studied

Researchers followed 1,545 adults diagnosed with epilepsy or unprovoked seizures from 2000 to 2010 at two First Seizure Clinics in Melbourne, Australia. Diagnoses were assigned by epileptologists, and people with high-grade brain tumors were excluded.

Clinic records were linked with the Australian National Death Index for follow-up extending up to 20 years. Researchers compared observed deaths with population death rates matched by age, sex, and calendar year. They also examined mortality according to pre-existing conditions, including problematic alcohol or substance use, psychiatric disorders, cancer, and cardiac or neurological conditions.

What they found

Overall, 282 people, or 18%, died during follow-up. The number of deaths was about twice that expected based on population rates, with an all-cause SMR of 2.0 (95% CI 1.8–2.3). Excess mortality was observed for up to 15 years after diagnosis at both clinics.

Among 1,375 people with information on pre-existing conditions, the SMR was higher in those with at least one such condition: 2.6 (95% CI 2.2–3.0), compared with 1.4 (95% CI 1.1–1.8) among those without a recorded condition. The subgroup reporting problematic alcohol or substance use, with or without a psychiatric disorder, had the highest SMR at 5.8 (95% CI 4.5–7.6).

Limits of the evidence

This was an observational study, so it cannot establish that epilepsy, substance use, or another condition caused the deaths. The abstract does not report causes of death, seizure control, treatments, or changes in health over time. Information about pre-existing conditions was unavailable for 170 participants, and the abstract provides limited detail about how these conditions were identified. The participants came from two specialist clinics in one Australian city, so the findings may not apply to every person with epilepsy or an unprovoked seizure. An SMR describes mortality across a group and does not predict an individual person’s outcome.

For families and caregivers

Adults diagnosed with epilepsy or an unprovoked seizure in these two clinics experienced persistent excess mortality compared with the general population. The relative difference was greatest among people with pre-existing health concerns, particularly reported problematic alcohol or substance use. These findings may help with patient counselling and identify groups warranting further examination, but they do not establish what caused the increased mortality.

What to watch next

Further studies could examine specific causes of death and investigate how seizure control, treatment, mental health, substance use, and other medical conditions are associated with mortality over time.

Terms in this summary

First Seizure Clinic

A specialist clinic that evaluates people following a first suspected seizure or a new epilepsy or unprovoked seizure diagnosis.

Unprovoked seizure

A seizure occurring without an identified immediate provoking factor.

Epileptologist

A doctor who specializes in diagnosing and treating epilepsy and seizures.

All-cause mortality

Deaths from any cause during the study period.

Standardized Mortality Ratio (SMR)

A comparison between observed deaths in a study group and expected deaths based on population rates. An SMR of 2.0 means about twice as many deaths were observed as expected.

95% confidence interval

A range expressing uncertainty around an estimated result.

Observational study

A study in which researchers observe outcomes without assigning participants to treatments or exposures.