Injury type and sociodemographic characteristics of youth with non-traumatic acquired brain injury: a population data linkage study

Aim To describe injury types and sociodemographic characteristics of young people with non-traumatic acquired brain injury (NT-ABI).Methods We conducted a national cross-sectional study of all 1–24-year-olds in the 2021/22 Estimated Resident Population using linked administrative data from the Integrated Data Infrastructure. NT-ABI was classified as birth-related or non-birth. Non-birth NT-ABI was further categorised into hypoxia, vascular events, brain tumors, infection, metabolic encephalopathy, and other causes. Observed NT-ABI rates were calculated overall and by sex, age group, ethnicity, area-level deprivation quintile, and rurality. Group differences were tested using chi-square tests (α = 0.05).Results Among 1,483,467 individuals, 40,290 (2.7%) had an NT-ABI: 1.6% birth-related and 1.1% non-birth. Infections were the most frequent non-birth cause (0.59%), followed by hypoxia (0.35%). Males had higher rates than females for any NT-ABI (3.0% vs 2.4%). Māori and Pacific peoples experienced higher rates than European and Asian groups for several types of NT-ABI. Clear deprivation gradients were observed with higher rates among those living in the highest levels of deprivation. Birth-related NT-ABI was higher in rural versus urban areas, however after adjustment for deprivation, age, sex, and ethnicity, the difference between rural and urban births was not significant.Conclusions NT-ABI affects a meaningful proportion of young people in New Zealand, with marked sociodemographic disparities highlighting the need for targeted prevention and equitable access to rehabilitation.