Difference in the characteristics of mortality reports during a heatwave period: retrospective analysis comparing deaths during a heatwave in January 2014 with the same period a year earlier

OBJECTIVES: To describe the characteristics of deaths reported to the Coroners Court of Victoria (CCOV) during Victoria’s last heatwave (14–17 January 2014) and subsequent 4 days (18–21 January) using medicolegal data obtained from both the police investigation report and the pathologist’s report. DESIGN, SETTING AND PARTICIPANTS: A single-jurisdiction population-based retrospective analysis of consecutive heat-related deaths (HRDs) reported to the CCOV between 14 and 21 January 2014 with a historical comparison group. MAIN OUTCOME MEASURES: Descriptive statistics were used to summarise case demographics, causes of death and the types of investigations performed. The cases from 2014 were subgrouped into HRD and non-HRD. RESULTS: Of the 222 cases during the study period in 2014, 94 (42.3%) were HRDs and 128 (57.7%) were non-HRDs. HRDs were significantly older than non-HRDs (70.5 years: SD=13.8 vs 61.0 years: SD=22.4, t(220)=3.60, p<0.001, 95% CI 4.3 to 14.6). The most common primary cause of death in HRDs was circulatory system disease (n=57, 60.6%), which was significantly higher when compared with non-HRDs (n=39, 30.5%; χ(2)=20.1, p<0.001, OR 3.5, 95% CI 2.0 to 6.2). HRDs required significantly greater toxicology investigation (89.4% (n=84) vs 71.9% (n=92); χ(2)=10.9, p<0.001, OR 3.3, 95% CI 1.54 to 7.03) and greater vitreous biochemistry testing (40.4% (n=38) vs 16.4% (n=21); χ(2)=16.0, p<0.001, OR 3.5, 95% CI 1.9 to 6.5). CONCLUSIONS: A heatwave places a significant burden on death investigation services. The inclusion of additional laboratory tests and more detailed circumstantial information are essential if the factors that contribute to HRDs are to be identified.