Growing Inequities in Median Age of Death and Obesity Prevalence Between Australian Major Cities and Remote Areas: A National, Longitudinal, Spatial Analysis

Background: Obesity significantly contributes to longevity, with 25-year-old Australians experiencing reduced life expectancy of 8.3 years (men) and 6.1 years (women) compared to healthy-weight peers. Given Australia's diverse geographical composition, this study examined trends in median age of death and obesity prevalence by remoteness over time. Methods: = 5) and Socio-Economic Indexes for Areas (SEIFA) deciles. Mixed-effect linear regression models examined differences by remoteness while adjusting for state/territory and area-level deprivation. Temporal inequities were assessed using the Slope Index of Inequality (SII). Results: Persistent and widening inequities in median age of death (2018-2022: male SII -3.6, 95% CI -4.9 to -2.3; female SII -2.5, 95% CI -3.8 to -1.2) and obesity (2022: male SII 11.7, 95% CI 10.4-12.9; female SII 12.5, 95% CI 11.1-13.9) were observed between major cities and remote areas. Obesity prevalence increased across all Australian areas, with smallest increases in major cities (men 3, women 0.5 percentage points) but substantially greater increases in outer regional areas (men 11, women 7 percentage points), creating a clear divergence in geographic inequity. Marked disparities in obesity prevalence existed across major cities, regional and remote areas. Conclusions: Geographic disparities were apparent in obesity prevalence and median age of death, as well as increasing inequities in both median age of death and obesity prevalence among Australian major cities, regional and remote areas. These findings highlight the urgent need for targeted public health interventions, particularly in regional and remote areas, to address Australia's growing health inequities.