Impacts of Extreme Heat on Accident & Emergency Attendances in Hong Kong: A Territory-wide Retrospective Cohort Study

Abstract

Introduction 

Increasing prevalence of extreme heat events in subtropical climates such as Hong Kong  exacerbates heat-related morbidities[1]. This study aims to investigate how increasing ambient temperatures correlates with territory-wide Accident and Emergency (A&E) attendances.

Method 

Daily A&E attendances, triage categories 1-5 (T1-T5), ages (0-14, 15-64, 65+) and sex were extracted from the Clinical Data Analysis and Reporting System for a study period of 2014-06-30 to 2023-12-31. Extreme heat events are classified as ‘Very Hot Weather Warning’ days (VHWWD) issued by the Hong Kong Observatory. Stepwise multivariable linear regression models were applied, employing listwise deletion for missing data.

Results

VHWWD (n = 606) (β = 0.217, 95% CI: 0.025-0.926, p < 0.001) were associated with higher A&E attendances (n = 3,286,736), showing a positive correlation against most subgroups. For triage categories, T4 attendances (β = 0.797, 95% CI: 1.145-1.229, p < 0.001) showed the strongest positive correlation to VHWWD, and was similarly exhibited in T3 (β = 0.274, 95% CI: 0.614-0.731, p < 0.001). Conversely, T1 (β = 0.039, 95% CI: 1.191-2.905, p < 0.001) and T5 (β = 0.040, 95% CI: 0.116-0.509, p < 0.001) demonstrated mildly positive correlation to VHWWD. Additionally, VHWWD corresponded with increased A&E attendances across all age groups, with 15-64 (β = 1.118, 95% CI: 0.390-3.524, p < 0.001) illustrating a greater increase; 0-14 (β = 0.635, 95% CI: 0.365-3.509, p < 0.001) and 65+ (β = 0.826, 95% CI: 0.677-3.781, p < 0.001) exemplified a weaker correlation. VHWWD did not affect either sex.

Conclusion

T4 attendances and ages 15-64 were most significantly impacted on VHWWD, subsequently influencing A&E attendances. The continual rise in temperature necessitates strategic allocation of healthcare resources to address increasing semi-urgent cases.