Trends in the Prevalence of Asthma in Korean Children: A Population-Based Study From 1995 to 2022.

Purpose: We investigated the prevalence of asthma and its risk factors in Korean children in 2022, comparing the prevalence with previous data to identify trends in the prevalence of childhood asthma over time.

Methods: This nationwide cross-sectional study enrolled 4,038 children aged 6-7 years and 4,269 children aged 12-13 years from 213 randomly selected elementary schools in 2022. The prevalence of asthma in 2022 was compared with those in 1995, 2000, and 2010, with subgroup comparisons classified by gender. A modified International Study of Asthma and Allergies in Childhood questionnaire assessed asthma prevalence with environmental factors.

Results: The prevalence of ''asthma diagnosis ever' in children aged 6-7 years was 9.1%, 9.4%, and 10.4% in 1995, 2000, and 2010, respectively, which was decreased in 2022 (2.1%, < 0.001). The prevalence of 'current asthma' in children aged 6-7 years showed fluctuations (3.5%, 2.0%, 4.2%, and 0.6% in 1995, 2000, 2010, and 2022, respectively) without showing a significant trend. The prevalence of 'asthma diagnosis ever' and 'current asthma' in children aged 6-7 years was significantly higher in males than in females. The prevalence of 'asthma diagnosis ever' in children aged 12-13 years was 3.1% in 1995, with a significant increasing trend in 2000 (5.8%) and 2010 (7.5%), followed by a decrease in 2022 (3.4%). Male sex, a history of bronchiolitis in early life, allergic rhinitis diagnosis ever, and atopic dermatitis diagnosis ever were associated with 'asthma diagnosis ever' in children aged 6-7 years. For children aged 12-13 years, male sex and history of bronchiolitis in early life were independently associated with 'asthma diagnosis ever.'

Conclusions: Childhood asthma prevalence has decreased, varying by asthma definition. The study's findings provide important information for establishing prevention and management strategies of childhood asthma.