Assessing heatwave impacts on cause-specific emergency department visits in urban and rural communities of Queensland, Australia

Background Heatwave impact on morbidity of people in rural areas has rarely been assessed in prior studies, and recently published literature has documented heatwave impact on a wide spectrum of diseases, for example, ear and eye diseases. Objectives To examine the associations between heatwaves and cause-specific emergency department visits (EDVs) across eight communities in both urban and rural regions throughout Queensland, Australia. Methods Daily data on EDVs, air pollution and climatic conditions during the 1st January 2013 to the 31st December 2015 were obtained from relevant government agencies. Heatwave was defined as ≥ 95th percentile of the mean temperature for three or more consecutive days in each community. A quasi-Poisson generalized additive model with a distributed lag non-linear model was used to assess the heatwave impacts on EDVs. Random effect meta-analysis was performed to investigate the effects of heatwaves on cause-specific EDVs across the urban and rural regions as well as the whole Queensland. The causes of EDVs investigated in this study were infectious and parasitic diseases (ICD code: A00–B99), endocrine, nutritional and metabolic diseases (E00–E90), mental and behavioural disorders (F00–F99), diseases of the nervous system (G00–G99), diseases of the ear and mastoid process (H60–H95), diseases of the circulatory system (I00–I99), diseases of the respiratory system (J00–J99), diseases of the skin and subcutaneous tissue (L00–L99), diseases of the musculoskeletal system and connective tissue (M00–M99), diseases of the genitourinary system (N00–N99), and injury, poisoning and certain other consequences of external causes (S00–T98). Results The meta-analysis results showed that there were significant effects of heatwaves on total EDVs and a wide-spectrum of cause-specific EDVs. For example, EDVs for endocrine, nutritional and metabolic diseases (RR: 1.18, 95% CI: 1.04 – 1.34), diseases of the nervous system (RR: 1.09, 95% CI: 1.02 – 1.17), and diseases of the genitourinary system (RR: 1.05, 95% CI: 1.00 – 1.09) increased substantially during heatwave days. The effect of heatwaves on total EDVs was similar for rural (RR: 1.04, 95% CI: 1.01 – 1.07) and urban regions (RR: 1.04, 95% CI: 1.00 – 1.07). Conclusions A wide range of diseases were sensitive to heatwave impacts. Residents in urban and rural areas were all vulnerable to heatwave impacts, calling for heat adaptation measures to be undertaken in Queensland, Australia.