Children's asthma hospitalisations in Queensland vary greatly depending on season, location and child's age and sex, according to a comprehensive QUT study that analysed 20 years of asthma admissions for those aged 0-19 years.
Hot desert and arid regions consistently showed the highest asthma risk, at times exceeding nine times the state average
Tropical rainforest zones, previously protective, showed a notable increase in asthma risk in recent years
Seasonal patterns of asthma hospitalisations vary distinctly across climate regions and age groups
The researchers' findings provide important evidence base for health planning and policy. They examined asthma-related hospital admissions from 2000 to 2019 for temporal, spatial and seasonal patterns across Queensland's diverse climate zones.
First author, PhD researcher Ms Jialu Wang, from QUT's School of Public Health and Social Work, said the risk for asthma hospitalisation was consistently higher in arid and semi-arid regions, likely related to dry conditions and airborne dust.
"Hot desert regions had the highest relative risks, at times exceeding nine times the state average before declining in later years," Ms Wang said.
"Hot semiarid and tropical savanna regions showed persistently elevated risk across the entire study period. Tropical rainforest zones generally showed lower risks in most years, though risk in these areas increased notably toward the end of the study period.
"We found that age-specific peak times for hospitalisations differed - for children aged 0 to 4, the peak was in May. Across all age groups, boys showed a stronger February peak while girls showed a broader winter pattern extending into July.
"Our analysis found that boys had higher hospitalisation rates at ages 0-4, 5-9 and 10-14, whereas female had higher rates during adolescence, aged15-19.
"These patterns are consistent with seasonal circulation of respiratory viruses in the colder months and differ from Australia's temperate regions, where peaks occur in February and November, suggesting Queensland has different climate conditions and triggers."
A major finding was that hospital admissions for the 0-4 age group had more than halved during the 20-year period, while admission rates had increased among older age groups. However, this decline might not fully reflect a true reduction in asthma burden, as changes in diagnostic and admission practices over time might also have played a role.
"Age-specific asthma hospitalisation rates changed over time, possibly reflecting shifts in physiological development, health policy and lifestyle behaviours," Ms Wang said.
"The drop in 0-4 admissions may in part reflect improved asthma management, though changes in how acute episodes are diagnosed and recorded cannot be ruled out.
"During the 20-year period, asthma guidelines changed several times, with strengthened preventative inhaler use, control-based health plans, asthma-friendly school initiatives and greater availability of reliever inhalers."
Ms Wang said the findings provided an evidence base for policy planning.
"All these initiatives may have supported earlier recognition and management of asthma and may have contributed to declines in hospital admissions after 2012."
The QUT research team comprised Ms Wang, her supervisor Professor Wenbiao Hu and Dr Javier Cortes-Ramirez, from QUT's School of Public Health and Social Work, and Professor Janet Davies from QUT School of Biomedical Sciences.
The study, Spatial and Temporal Patterns in Childhood and Adolescent Asthma Hospitalisations in Queensland, Australia: A 20-Year Ecological Study Across Climate Zones, was published in The Medical Journal of Australia.
(Image above, from top left: Professor Janet Davies, Professor Wenbiao Hu, Ms Jialu Wang and Dr Javier Cortes-Ramirez.)
