Healthcare Costs of Emergency Department Presentations Related to Heatwave Intensity and Severity

Abstract

BACKGROUND AND AIM: The health impacts of heatwaves are a growing public health concern. However, little is known about the healthcare costs of heatwave-related morbidity. This study aims to examine the relationship between heatwaves and costs of emergency department (ED) presentations and to quantify heat-attributable presentations and costs in Adelaide, South Australia. METHODS: Daily data on ED presentations and associated costs for the period 2014-2017 were obtained from the South Australian Department of Health and Wellbeing. Heatwave severity and intensity were determined using the excess heat factor (EHF) index, obtained from the Australian Bureau of Meteorology. A distributed lag non-linear model (DLNM) was used to quantify the cumulative risk of heatwave-intensity over a lag of 0-7 days on ED presentations and costs. Effects of heatwaves were estimated relative to no heatwave. The number of ED presentations and costs attributable to heatwaves was calculated separately for two EHF severity categories (low-intensity and severe heatwaves). Subgroup analyses by disease-diagnosis groups and age categories were performed. RESULTS:For most disease diagnosis and age categories, low-intensity and severe heatwaves were associated with higher rates of ED presentations and costs. We estimated a total of 1,161 (95% empirical confidence interval (eCI): 342, 1,944) heatwave-attributable all-cause ED presentations and an associated healthcare costs of AU$1,020,330 (95% eCI: 224,851, 1,804,745) during the warm seasons of 2014-2017. Heat-related illness was the disease category contributing most to ED presentations and costs. CONCLUSIONS:Heatwaves produced a significant case-load and cost burden to the ED. The young and old peoples were most susceptible to heat. Developing tailored interventions for the most vulnerable populations may help reduce the health impacts of heatwaves and to minimise the cost burden to the healthcare system. KEYWORDS: Temperature, Climate, Temperature extremes