Differences in Epilepsy Etiology, Type, Syndrome, and Severity Between Māori and Non-Māori-Non-Pasifika Children With Epilepsy in New Zealand

BACKGROUND AND OBJECTIVES: The World Health Organization's Intersectoral Global Action Plan on Epilepsy and other Neurologic Disorders 2022-2031 aims to minimize epilepsy burden, with an emphasis on Indigenous peoples. Māori, the Indigenous peoples of New Zealand, have a similar prevalence of treated epilepsy to non-Māori yet suffer an increased epilepsy burden. This study aims to describe epilepsy etiology, syndrome, and severity in Māori children compared with non-Māori-non-Pasifika children. METHODS: Retrospective population-based study using the New Zealand Pharmaceutical Collection. Medical records were reviewed to compare epilepsy etiology, type, syndrome, and severity between Māori and age-matched and sex-matched non-Māori-non-Pasifika children (younger than 18 years) with treated epilepsy. Period prevalence of etiology was compared: logistic regression (odds ratio, OR) for comparisons of within-cohort proportions and Poisson regression (rate ratio, RR) for comparison of population prevalence. RESULTS: Cohort of 337 Māori and 421 non-Māori-non-Pasifika children (female: 45.4% Māori and 46.6% non-Māori-non-Pasifika). The median age of first seizure was 3.0 years for Māori (interquartile range [IQR]: 0.9-8.0) and 4.0 years for non-Māori-non-Pasifika (IQR: 1.3-8.0). Māori children were more likely to live in high deprivation areas (quintile 5: 48.4% Māori vs 17.3% non-Māori-non-Pasifika). Māori children were more likely to have a preventable cause of their epilepsy than non-Māori-non-Pasifika children (RR: 2.32; 95% CI 1.41-3.80) and more likely to have a structural (RR: 1.43, 95% CI 1.04-1.97) or infectious (RR: 4.72, 95% CI 1.43-15.8) etiology. After adjustment for socioeconomic status and rurality, there was no longer evidence for a difference by ethnicity. Focal epilepsy was the most common epilepsy type (65.6% Māori and 59.4% non-Māori-non-Pasifika), followed by genetic epilepsies (20.2% Māori and 21.9% non-Māori-non-Pasifika). An epilepsy syndrome was identified in 26% of Māori and 36% of non-Māori-non-Pasifika children. Māori children were less likely to have a self-limited epilepsy syndrome (OR: 0.51, 95% CI 0.30-0.83) or developmental and epileptic encephalopathy (OR: 0.59, 95% CI 0.40-0.88) but more likely to have intellectual disability and epilepsy (OR: 1.65, 95% CI 1.18-2.32). DISCUSSION: Health inequities exist for Māori children who are twice as likely to have preventable epilepsy than non-Māori-non-Pasifika children. This inequity is largely driven by socioeconomic status and rurality.