Association between maternal mental health-related hospitalisation within the first postnatal year and potentially avoidable hospitalisation among their children in the Northern Territory of Australia, using 16 years of linked administrative data

Abstract Purpose Children of mothers with postnatal mental health conditions are at increased risk of adverse health and psychosocial outcomes. This study assessed the association between postnatal mental health-related hospitalisation (MHrH) of Aboriginal and non-Aboriginal mothers and the risk of potentially avoidable hospitalisations (PAH) among their children when aged 12 to 60 months. Methods This is a whole-population retrospective cohort study using individual-level linked records for 59,159 children born in the Northern Territory from 2002 to 2017. Children were exposed if their mothers had at least one episode of MHrH within the first postnatal year. Incidence rates of PAH were determined, and weighted multilevel mixed-effect survival analysis was used to estimate the weighted hazard ratio (wHR) of PAH associated with exposure status. Overlap weights were used for confounder adjustment. Results The incidence rate (per 1,000 child-months) of PAH amongst 20,718 children born to Aboriginal mothers was 11.85 (95%CI: 10.27–13.67) in exposed and 8.94 (95%CI: 8.75–9.13) in non-exposed; and, amongst 38,441 children born to non-Aboriginal mothers, 1.62 (95%CI: 1.13–2.33) in exposed and 2.08 (95%CI: 2.01–2.14) in non-exposed. After adjustment, exposed children born to Aboriginal mothers had a 24% higher risk of PAH (wHR: 1.24; 95%CI: 1.04–1.47) compared to their non-exposed counterparts, with a weighted population attributable fraction (wPAF) of 0.55% (95%CI: 0.09–1.07). No corresponding difference in risk of PAH was demonstrated among children born to non-Aboriginal mothers (wHR: 0.73; 95%CI: 0.50–1.08). Conclusion Exposed children of Aboriginal mothers experienced a higher risk of PAH compared to non-exposed children. Meaningful reductions in PAH require culturally grounded, comprehensive maternal and child health programs that respond to the broader determinants underlying preventable child hospitalisations, including maternal mental health and related issues.