Spatial Patterns of Heatwave-Related Mortality Among Older Australians: A Case Time-Series Analysis — The Association Specialists
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  3. Spatial Patterns of Heatwave-Related Mortality Among Older Australians: A Case Time-Series Analysis

Spatial Patterns of Heatwave-Related Mortality Among Older Australians: A Case Time-Series Analysis (23768)

Sabrina Guensche 1 , Olga Anikeeva 1 , Matthew Borg 1 , Blesson Varghese 1 , Peng Bi 1
  1. Adelaide University, Adelaide, SOUTH AUSTRALIA, Australia

 

Please consider this abstract for the AEA Student Conference Award.

Background

Older adults are particularly vulnerable to heat exposure¹, but evidence on heatwave-related mortality and its spatial variation across Australia remains limited. This study examined heatwave-related mortality among Australians aged 65 years and older across 2,359 local areas from 2012 to 2022 and incorporated area-level vulnerability factors.

Methods

Daily mortality data were obtained from the Australian Bureau of Statistics for Statistical Area Level 2 (SA2) regions. Heatwave exposure was assigned at the SA2 level using gridded climate data and defined by the Excess Heat Factor². A two-stage case time-series analysis was applied, combining area-specific quasi-Poisson distributed lag non-linear models with multivariate meta-regression³. Principal component analysis was used to account for spatial heterogeneity³. Associations were assessed by age, sex, socioeconomic disadvantage, climate zone, and remoteness, and estimates were downscaled to SA2 for mapping. Future heatwave-related mortality was projected for the 2030s and 2050s using climate model projections.

Results

At the national level, heatwave days were associated with increased mortality among adults aged 65 years and older. Relative risks were 1.09 (95% CI: 1.03–1.14) during severe heatwaves and 1.31 (95% CI: 1.14–1.50) during extreme heatwaves. Risks were elevated in older age groups, while little evidence of increased mortality was observed among those aged 65–74 years. Males showed higher risks than females, specifically during extreme events. Mortality burden varied spatially across Australia, with higher-risk areas concentrated in inland Queensland, inland New South Wales, northern Australia, and inland South Australia. Future projections indicated an increasing mortality burden, particularly during extreme heatwaves and under scenarios without adaptation.

Conclusion

Heatwave-related mortality among older Australians increases with heat intensity and varies substantially across SA2 regions. These findings can inform targeted interventions and heat-health adaptation strategies for ageing populations.

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