Motor vehicle accidents, suicides, and assaults in epilepsy: A population-based study

Background: The goal of our study was to compare the incidence of motor vehicle accidents (MVA), attempted or completed suicides, and injuries inflicted by others between individuals with and without epilepsy. Methods: Individuals with and without epilepsy were identified using linked administrative databases between 1996 and 2003 in a Canadian health region with a 1.4 million population. We used a validated epilepsy case definition: anyone who had 2 physician claims, one hospitalization, or one emergency room visit coded with an International Classification of Diseases (ICD)-9-CM or ICD-10 epilepsy code any time during a 2-year period. Four subjects without epilepsy were matched to one patient with epilepsy by age (within 1 year) and sex. The incidence of MVAs, attempted or completed suicides, and inflicted injuries was assessed in 2003-2004. Outcomes were adjusted using the Elixhauser comorbidity index. Results: A total of 10,240 individuals with epilepsy and 40,960 individuals without epilepsy were identified. Mean age was 39.0 ± 21.3 years (range 0.12-99.4) and 48.5% were female. One-year odds ratios before and after adjustment for comorbidity were 1.83 (95% confidence interval [CI] 1.33-2.54) and 1.38 (95% CI 0.97-1.96) for MVAs, 4.32 (95% CI 2.79-6.69) and 1.32 (95% CI 0.81-2.15) for attempted or completed suicides, and 3.54 (95% CI 2.66-4.72) and 1.46 (95% CI 1.04-2.03) for injuries inflicted by others. Conclusion: In this cohort-controlled population-based study, once important medical and psychiatric comorbidities were adjusted for, people with epilepsy were not more likely to attempt suicide or experience MVAs, but were still more likely to be assaulted compared to those without epilepsy.