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Is asthma in children still increasing? 20-year prevalence trends in northern Sweden
Linnea Hedman1, Martin Andersson1, Anders Bjerg2
1Department of Public Health and Clinical Medicine, The OLIN unit, Umeå University, Umeå, Sweden.
Insights
Asthma diagnoses in children doubled between 1996 and 2017, but asthma symptoms and severity remained stable. This suggests earlier and more frequent diagnoses for mild childhood asthma cases.
Area of Science:
- Pediatric respiratory health
- Epidemiology of childhood asthma
Background:
- Investigating asthma prevalence and trends in 8-year-old children in Norrbotten, Sweden.
- Examining associations between asthma diagnosis, symptoms, medication use, and severity over time.
Purpose of the Study:
- To describe prevalence trends of asthma in children.
- To analyze the association between asthma diagnosis and morbidity indicators.
Main Methods:
- Utilized data from the Obstructive Lung Disease in Northern Sweden (OLIN) studies.
- Conducted parental questionnaire surveys with pediatric cohorts in 1996, 2006, and 2017.
- Included 3,430 (1996), 2,585 (2006), and 2,785 (2017) children aged 8 years.
Main Results:
- Wheezing prevalence remained stable (approx. 10%) across the study years.
- Physician-diagnosed asthma significantly increased from 5.7% to 12.2% (p < .001).
- Asthma medication use also rose, yet asthma symptoms and severity decreased among diagnosed children.
Conclusions:
- Physician-diagnosed asthma doubled without a corresponding increase in asthma morbidity.
- Increased diagnoses may be attributed to earlier identification of mild asthma cases.
- Stable wheezing prevalence contrasts with rising asthma diagnoses in this pediatric population.
Background:
In the present study, we describe prevalence trends of asthma and investigate the association with asthma symptoms, use of asthma medication, and asthma severity among 8-year-old children in Norrbotten, Sweden in 1996, 2006, and 2017.
Methods:
Within the Obstructive Lung Disease in Northern Sweden (OLIN) studies, three pediatric cohorts were recruited in 1996, 2006, and 2017 respectively. Identical methods were used; all children in first and second grade (median age 8 years) in three municipalities were invited to a parental questionnaire survey, completed by n = 3430 in 1996 (97% participation), n = 2585 in 2006 (96%), and n = 2785 in 2017 (91%). The questionnaire included questions about respiratory symptoms and diagnosis, treatment, and severity of asthma.
Results:
The prevalence of wheezing was stable during the study, 10.1% in 1996; 10.8% in 2006; and 10.3% in 2017, p = .621, while physician-diagnosed asthma increased: 5.7%, 7.4%, and 12.2%, p < .001. The use of asthma medication in the last 12 months increased: 7.1%, 8.7%, and 11.5%, p < .001. Among children diagnosed with asthma, the prevalence of asthma symptoms, the impact on daily life, and severe asthma decreased, while the use of inhaled corticosteroids increased from 1996 until 2017.
Conclusion:
The prevalence of wheezing was stable among 8-year-old in this area from 1996 to 2017, while the prevalence of physician-diagnosed asthma doubled but without an increase in asthma morbidity. The increase of physician-diagnosed asthma without a coincident increase in asthma morbidity can partly be explained by more and earlier diagnosis among those with mild asthma.
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