Abstract
Background: Epilepsy is a serious neurological disorder which affects all ages, social classes, and ethnicities. In 2022 the World Health Organization adopted the Intersectoral Global Action Plan on Epilepsy and other Neurological Disorders 2022-2031 (IGAP). The IGAP emphasises the need for improved epilepsy healthcare and the elimination of health disparities in high-risk groups such as Indigenous peoples. Māori, the Indigenous peoples of Aotearoa New Zealand, make up 27% of the Aotearoa New Zealand paediatric population and typically experience worse health outcomes and access to healthcare. Aotearoa New Zealand studies have reported that, despite similar levels of treated epilepsy for Māori and non-Māori children, Māori individuals with epilepsy are more likely to present to the emergency department, are more likely to be admitted to hospital, and are more likely to have a higher mortality rate. The aim of this PhD thesis is to describe the types, aetiologies, comorbidities, outcomes, and management of epilepsy in Māori children and compare these to non-Māori-non-Pasifika children with epilepsy.
Methods: This thesis is a population-based retrospective cohort study using a Kaupapa Māori guided approach. The cohorts were derived from a larger cohort of previously identified children (<18 years) with treated epilepsy who had been dispensed ≥1 antiseizure medication in 2015 from the Northland, Auckland, and Wellington regions. All of the Māori children (n=337) with treated epilepsy were included and compared to an age and sex matched comparison cohort of non-Māori-non-Pasifika children (n=421). Medical records were examined to investigate the following aspects (variables) of epilepsy in the children: (1) the type, syndrome, and aetiology of epilepsy; (2) the provision of epilepsy care; (3) the epilepsy related outcomes and (4) the neurodevelopmental comorbidities; All variables were analysed by comparing the proportion of children with each aspect in the Māori cohort to the proportion of children with each aspect in the non-Māori-non-Pasifika cohort. For analysis of epilepsy type and aetiology an additional analysis was performed which compared the prevalence of each epilepsy type and aetiology in the New Zealand population between the two groups of children.
Results: In the proportional analysis, differences in the epilepsy types was identified between the Māori and non-Māori-non-Pasifika groups. Māori children (relative to non-Māori-non-Pasifika children) were less likely to have a self-limited epilepsy syndrome (OR:0.51; 95% CI 0.30-0.83), less likely to have a developmental and epileptic encephalopathy (OR:0.59; 95% CI 0.40-0.88), and more likely to have an intellectual disability and epilepsy syndrome (OR:1.65; 95% CI 1.18-2.32). Māori children were more likely to have a structural (OR:1.5; 95% CI 1.08-2.16) and infectious aetiology (OR:4.7; 95% CI 1.66-16.50), and less likely to have a genetic aetiology (OR:0.70; 95% CI 0.52-0.95). At a population level, Māori were more likely to have a structural (RR: 1.43; 95% CI 1.04 – 1.97) and infectious (RR:4.72; 95% CI 1.41 – 15.8) aetiology but there was no difference in the prevalence of a genetic aetiology (RR: 0.93; 95% CI 0.72 – 1.21). Māori children were more likely to have a preventable aetiology than non-Māori-non-Pasifika children in both the proportional analysis (OR: 2.72 95% CI 1.69 – 4.45) and at a population level (RR: 2.72 95% CI 1.41 – 3.80). After adjustment for socioeconomic status and rurality, Māori children within the study cohort were 2.5 times (95% CI 1.49-4.22) more likely to have a preventable aetiology, however at a population level statistical significance was no longer seen (RR: 1.44; 95% CI 0.76 – 2.75).
Inequities in the management of epilepsy were identified. After presenting for their first seizure, Māori children were more likely to be discharged home from the emergency department (OR:1.72; 95% CI 1.12 - 2.66). When clinically indicated, Māori children were less likely to receive an MRI (OR: 0.28; 95% CI 0.18 – 0.45) and less likely to see a paediatric neurologist (OR: 0.44; 95% CI 0.30 – 0.63). Māori children, compared to non-Māori-non-Pasifika children, waited 3 weeks longer for an EEG, 12 weeks longer for an MRI, 4.5 weeks longer to see a medical specialist in the outpatient department, and 5 years longer to see a paediatric neurologist.
Regarding epilepsy related outcomes and comorbidities, Māori children were no more likely to have drug-resistant epilepsy (OR:1.15; 95% CI 0.85 – 1.55) but less likely to be seizure free at two- (OR: 0.47; 95% CI 0.27 – 0.78) and five-years (OR: 0.48; 95% CI 0.31 – 0.72) after presentation for epilepsy. Māori children were more likely to be diagnosed with cerebral palsy (OR: 1.76; 95% CI 1.19 – 2.61) and hearing impairment (OR: 3.35; 95% CI 1.58 – 7.74), and less likely to be diagnosed with Autistic Spectrum Disorder (OR: 0.60; 95% CI 0.38 – 0.92).
Conclusions: This study is the first to analyse in-depth and describe epilepsy in Māori children and compare them to non-Māori-non-Pasifika children. A number of differences were identified including epilepsy type, aetiology and comorbidities. Concerningly, a substantial number of inequities were identified including more preventable epilepsy, worse access to medical specialists and investigations and less seizure freedom. This thesis highlights unequivocally that Māori children with epilepsy experience suboptimal epilepsy care and outcomes. Socioeconomic status and level of rurality contributed to many, but not all, of the identified inequities. Understanding epilepsy in Māori children is essential for the development of public health strategies that aim to improve epilepsy healthcare. In order to decrease epilepsy burden and achieve equitable outcomes, Aotearoa New Zealand needs to ensure that healthcare is accessible, delivered equitably, culturally appropriate, and responsive to the needs of our community.