Association between children's health-related quality of life, healthcare costs and socioeconomic position: Results from a longitudinal Australian-based study

•Between birth and 13 years, disadvantaged children incurred higher government healthcare costs.•Between ages 6 and 13 years disadvantaged children experienced lower HRQoL than advantaged children.•Parental stress and lone parenthood contributed to higher healthcare costs and lower children's HRQoL.•Children with special healthcare needs experienced higher service use and lower HRQoL.•Living in regional and remote areas was associated with lower use of health services.