Heatwave-related Mortality in Australia: Who's impacted the most?. (30th September 2020)

• Record Type: Journal Article
• Authors: Varghese, B; Beaty, M; Panchuk, S; Mackie, B; Chen, C; Jakab, M; Yang, T; Bi, P; Nairn, J
• Is Part Of: European journal of public health. Volume 30(2020)Supplement 5
• Publication Date: 2020-09-30
• Subjects: Epidemiology -- Europe -- Periodicals; Public health -- Europe -- Periodicals; 362.109405
• DOI: 10.1093/eurpub/ckaa165.377
• Languages: English
• ISSNs: 1101-1262

Abstract

Abstract: Background: The impacts of heatwaves on the risk of mortality have been well-documented worldwide. However, impacts are not equally spread across the population with certain subgroups and locations affected more than others, warranting local evidence to guide and improve prevention and adaptation strategies. The objectives of this study were to identify the person and area-level socio-demographic, health, and environmental factors that modify the heatwave-mortality association in Australia. Methods: Warm-season (October-March) mortality (2007-2017) were obtained from the Australian Bureau of Statistics. Heatwaves were defined using Excess Heat Factor, a normalised metric of heatwave severity. A time-stratified case-crossover design was used to model heatwave-mortality associations at the Statistical Areas 2 (SA2) spatial unit. Effect modification by person and area-level factors was assessed using interaction terms. Results: Nationally, mortality increased by 2% (Relative Risk-RR 1.02; 95%CI: 1.01-1.03) during heatwaves with 1418 excess deaths (95%CI: 723-2113). But impacts varied with the highest effect observed in Adelaide (RR 1.08; 95%CI: 1.04-1.12) and Regional Tasmania (RR 1.11; 95%CI: 1.04-1.18). A gradient of impact was found within locations, for example, vulnerable SA2s in Adelaide were featured by a higher proportion of people in rental housing, inaccessibilities (vehicle and internet), low vegetation, newer houses, and a prevalence of respiratory and psychological diseases. Person-level factors included those: renting privately, with a low English-speaking ability, with chronic health conditions (diabetes, asthma/chronic obstructive pulmonary diseases) and using antidepressants, anxiolytics and sedative medications. Conclusions: Our results, leveraging person and area-level linked data, highlight the need to consider contextual and individual risk factors and the importance of developing place-based targeted interventions to reduce heatwave health impacts. Key messages: Heatwaves increase mortality in Australia. Heatwave-vulnerability is determined by individual and community-level factors.