Heatwaves and emergency department visits in the single hospital of arid Central Australia – a time series study

BACKGROUND: The arid Central Australia will continue to experience increasing hotter temperatures. OBJECTIVES: This research assessed associations between heatwaves and all cause, and cause-specific emergency department (ED) visits for cardiovascular diseases, infectious diseases, kidney and urinary tract diseases (KD), mental disorders and respiratory diseases. METHODS: Daily ED visits data, 2010 to 2021, from Alice Springs Hospital, Central Australia, were obtained. Nine heatwave definitions based on combinations of mean temperature thresholds (≥90th, ≥95th, and ≥97th percentile) and durations (≥2, ≥3, and ≥4 consecutive days) during warm months were assessed in quasi-Poisson regression models. The ≥ 95th percentile for ≥2 consecutive days was the primary exposure, with remaining definitions assessed in exploratory analyses. RESULTS: A total of 50,324 ED visits were recorded. Heatwaves, ≥95th percentile of daily mean temperature for ≥2 days and ≥90th percentile temperature for ≥2 days, were associated with modest increases in all cause ED visits at lag 0 (HW2 relative risk - RR 1.02, 95% CI 0.97-1.07) compared to non-heatwave days. Significant increases in KD‑related ED visits were consistently observed for several heatwave thresholds including primary heatwaves exposure over several lag days (at lag 0-2 days cumulative RR 1.37, 95% CI 1.02-1.83). Increased risks of ED visits from heatwaves were also observed among people aged > 45 years. CONCLUSIONS: These findings suggest differential effects of heatwaves on ED visits in the single hospital in Central Australia and highlight need for emergency services preparedness within remote health service systems that is backed up by local demographic and health profiles.