Vulnerability-related disparities in early childhood healthcare costs in the Northern Territory, Australia: a population-based retrospective cohort study.

OBJECTIVE: Early childhood health and economic burdens are disproportionately distributed across population groups. We examined the vulnerability-related (First Nations status and remoteness) disparities of early childhood healthcare costs from birth to age 5 years and quantified the contribution of adverse perinatal outcomes, such as preterm birth (PTB), small-for-gestational-age (SGA) and low birthweight, to these disparities in the Northern Territory (NT), Australia. DESIGN AND PARTICIPANTS: We conducted a population-based retrospective cohort study of all singleton live births in the NT, Australia, between 1 July 2000 and 30 June 2016, using the Perinatal Trends dataset. Birth records were linked to hospitalisation, emergency department (ED) and national hospital costing data and followed to age 5. OUTCOMES AND ANALYSIS: Healthcare costs, adjusted to 2024 Australian Dollars (AUD), from a health system perspective, included hospitalisation and ED costs. A generalised linear model with log link and gamma distribution was fitted, and Oaxaca-Blinder decomposition was used to partition cost differences into explained (differences in population characteristics) and unexplained (differential effects/responses) components. RESULTS: The overall median hospitalisation costs per child were AUD 9608 (IQR: 4873 to 20 681) and ED costs AUD 2156 (IQR: 1075 to 4274) in the first 5 years. Among children with PTB and SGA, median hospitalisation costs were AUD 30 527 (IQR: 16 765 to 54 365) for First Nations and AUD 16 098 (IQR: 7577 to 28 048) for non-First Nations children; within this subgroup, costs were AUD 29 614 (IQR: 15 085 to 51 400) in remote areas compared with AUD 19 776 (IQR: 9620 to 33 263) in urban areas. After adjustment, mean hospitalisation costs were 98% higher for First Nations children (AUD 23 223 vs 11 716; difference AUD 11 507, 95% CI 10 798 to 12 215) and 19% higher for children in remote areas (AUD 19 454 vs 16 322; difference AUD 3132, 2479 to 3786); corresponding differences in mean ED costs were 67% (AUD 1866, 95% CI 1750 to 1982) and 17% (AUD 557, 95% CI 460 to 655). Remoteness-related disparities in hospitalisation costs were largely explained by child characteristics (85.7%; βE=-0.549, 95% CI -0.581 to -0.517), while disparities by First Nations status were primarily driven by differential cost responses (71%; βc=-0.606, 95% CI -0.651 to -0.561). For ED costs, characteristics explained 42% of the remoteness-related gap and 3.4% of the gap by First Nations status. CONCLUSIONS: Our findings highlight that vulnerability-related disparities in healthcare costs were substantial, with adjusted costs 67% to 98% higher for First Nations children and 17% to 19% higher for children in remote areas, and driven by distinct mechanisms. Thus, strategies addressing structural disadvantage and inequitable experiences are needed to reduce avoidable healthcare costs.