The extreme heat wave in Australia in 2009 resulted in significantly increased number of daily deaths. The circumstances that lead to deaths during extreme heat have not been explored before in Australia. This study aims to identify the individual and community risk factors for deaths during this extreme heat wave in Adelaide. A matched case-control study was conducted. Cases were those who died in the Adelaide metropolitan area during the heat wave period. For each case, two community controls were randomly selected, matched by age and gender. Face-to-face or telephone interviews were conducted to collect data of demographic information, living environment, social support, health status and behavioural changes during the heat wave. Descriptive analysis, as well as simple and multiple conditional logistic regressions were performed. In total, 82 deaths and 164 matched community controls were included in the analysis, with a median age of 77.5 (range 26.6–100.7). The multiple logistic regression model indicated that, compared with controls, the risk of death during the heat wave was significantly increased for people living alone (AOR = 42.31, 95 % CI 2.3, 792.8) or having existing chronic heart disease (AOR = 22.4, 95 % CI 1.7, 303.0). In addition, having air conditioning in bedrooms (AOR = 0.004, 95 % CI 0.00006, 0.28) and participating in social activities more than once a week (AOR = 0.011, 95 % CI 0.0004, 0.29) indicated significant protective effects. We have identified factors that could significantly impact on the likelihood of deaths during heat waves. Our findings could assist in the development of future intervention programs and policies to reduce mortality associated with a warmer climate.
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The study was supported by the Australian Research Council Linkage Project (LP110200820 to PBI et al) and the Department for Health and Ageing SA. Dr. Ying Zhang was an Australian National Health and Medical Research Council Public Health Training Fellow (602749).
Compliance with ethical standards
This project was approved by the Human Research Ethics Committees (HREC) from both the University of Adelaide (H-101-2010) and the South Australian DHA (376/06/2013). Due to the ethical sensitivity of the study, work was carried out within the DHA in SA as required by the ethical approvals. In order to collect deceased patients’ data from the hospitals’ medical records, ethical approvals were also obtained from each Ethics Committee of relevant hospitals. Consent from subjects participating in the study was received prior to conducting the study.
The authors declare that they have no competing interests.
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