Asthma Medication Use During a Bushfire: An Interrupted Time Series Analysis — The Association Specialists
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  3. Asthma Medication Use During a Bushfire: An Interrupted Time Series Analysis

Asthma Medication Use During a Bushfire: An Interrupted Time Series Analysis (24237)

Cathy Etherington 1 , Nina Lazarevic 1 , Jennifer Welsh 1 , Sotiris Vardoulakis 2
  1. Australian National University, Higgins, AUSTRALIAN CAPITAL TERRITORY, Australia
  2. University of Canberra, Canberra

Title: Asthma Medication Use During a Bushfire: An Interrupted Time Series Analysis

Background Wildfire smoke is a major source of fine particulate matter (PM2.5), which can exacerbate respiratory conditions such as asthma. Understanding how medication use changes during smoke events can help guide public health responses. This study investigated patterns of short acting beta agonist dispensations during and in the period following the 2019/20 bushfires in NSW and the ACT.

Methods An interrupted time series analysis was conducted using ARIMA modelling to assess changes in asthma medication dispensations associated with rising PM2.5 levels. Weekly dispensing data were analysed across the wildfire period and compared with pre‑event trends. Stratified analyses were performed by age group (<12 years, 12–64 years, ≥65 years) and sex to identify differences in dispensation patterns across the population subgroups.

Results Increases in PM2.5 concentrations were associated with a measurable rise in SABA dispensations. The increase was greatest among adults aged 65 years and over, who showed a marked escalation in demand during peak smoke exposure. Individuals aged 12 to 64 years demonstrated a smaller but still notable increase. In contrast, no clear change in dispensing patterns was observed among children under 12 years. Differences between the sexes were largest for the 12 to 64 years age group.

Conclusion SABA medication dispensations increased in response to elevated PM2.5 levels during the fire period, particularly among older adults. These findings highlight the heightened vulnerability of people aged 65 years and over during smoke events and underscore the importance of targeted public health messaging and preparedness strategies. Understanding medication demand during a bushfire crisis can support more responsive healthcare planning.