Spatiotemporal characteristics of asthma emergency department presentations in diverse geographical and climatic regions, Queensland, Australia.

Objective: Sudden acute episodes of asthma exacerbation are often treated by hospital EDs. It is hypothesised that determinants of acute asthma would differ across geographic regions. The objective of the present study was to detail seasonality, trends and spatiotemporal patterns of asthma ED presentations across Queensland (QLD), Australia, a state covering 1.8 million square kilometres, spanning multiple climates.

Methods: Six years of routinely collected data (2012 to 2017) from 28 major QLD public hospitals were extracted from Queensland Health's Emergency Data Collection. The dataset contained individual, episode-level asthma-like diagnoses of ED presentations. Seasonality and trends of acute asthma were assessed through multiplicative time-series analysis.

Results: The study consisted of 2192 days with a total of 65 012 asthma ED presentations in QLD. The 6-year average daily incidence rate was 270 asthma ED presentations per 100 000 population. The highest morbidity of asthma ED presentations occurred during the southern hemisphere winter months. Children showed a higher incidence rate compared to adults with males experiencing a higher incidence compared to females up until the age of 13, after which an inversion was observed persisting through adulthood. Seasonality of asthma ED presentations differed with latitude across QLD.

Conclusion: Asthma-related ED presentations exhibit spatiotemporal variation across QLD, which appears to be related to climate. Furthermore, aeroallergens and respiratory viruses may be responsible for asthma ED peaks outside the winter period. Socioeconomic status may influence asthma ED presentation rates between regions. This knowledge can guide ongoing management and assist public health policy response.