Current and projected healthcare costs for emergency department presentations under the changing climate

Abstract

Background: Existing studies have documented the link between emergency department (ED) presentations and high ambient temperatures; however, there is a lack of evidence about the temperature-cost dependencies and cost impact to the healthcare system. Methods: A time series analysis using distributed lag nonlinear models was used to explore the temperature-ED presentations and temperature-cost relationships and to estimate temperature-, cold-, and heat-attributable effects in Adelaide, South Australia. The potential impacts of future climate under different representative concentration pathway (RCP) emission scenarios were estimated for two future periods (2034-2037 and 2054-2057). Results: It is estimated that the number of baseline (2014-17) heat-attributable ED presentations was approximately 3,633 (95% empirical confidence interval (eCI): 694.7, 6,498.4) with associated ED costs of AU$4.7 million (95% eCI: 1.8, 7.5). Under RCP8.5 and with a constant population, heat-attributable ED presentations were projected to increase by 2.0% (95% eCI: 1.1, 2.9) and ED costs by 2.0% (95% eCI: 1.1, 2.8) during 2054-57. Non-significant declines in cold-attributable ED presentations and costs were observed. Under the three RCPs and assuming a medium population increase, the percentage increases in excess heat-attributable effects would range from 5.5% (95% eCI: 2.0, 9.1) to 7.5% (95% eCI: 3.1, 11.9) for ED presentations, and from 1.9% (95% eCI: 0.9, 2.8) to 2.5% (95% eCI: 1.3, 3.7) for ED costs during 2034-2037. Under RCP8.5, ED presentations and costs will increase by 14.7% (95% eCI: 6.9, 22.3) and 5.0% (95% eCI: 2.6, 7.1) during 2054-2057, respectively. There may be no change in cold-attributable deaths. Conclusions: Projected climate change is likely to have a substantial effect on the healthcare system with an increase in heat-associated emergency presentations and the associated costs. Greater health system resources will be required to meet these challenges unless effective adaptation strategies and public health prevention actions are adopted.