Prevalence and risk factors for childhood asthma: a systematic review and meta-analysis

Background: This study aimed to systematically review and perform a meta-analysis on epidemiological studies in order to estimate the global and regional prevalence and to identify risk factors associated with childhood asthma.

Methods: A comprehensive search of the PubMed, Embase, and Cochrane Library electronic databases was conducted for relevant literature published from their inception to March 31, 2023. The primary endpoint was the prevalence of childhood asthma. Secondary endpoint focused on the identification of risk factors associated with childhood asthma.

Results: A total of 1,547,404 children participated in the 164 studies selected for the meta-analysis. The overall prevalence of childhood asthma was 10.2% (95% CI: 9.5-11.0%), while the prevalence of childhood asthma in Asia, Europe, Latin America, North America, Oceania, Africa, or Eurasia were 10% (95%CI: 7-13%), 9% (95%CI: 7-12%), 14% (95%CI: 9-20%), 13% (95%CI: 12-14%), 23% (95%CI: 19-28%), 11% (95%CI: 7-19%), and 8% (95%CI: 2-27%), respectively. Moreover, the identified risk factors for childhood asthma included older age, male sex, obesity, parental smoking, high education of the mother, premature birth, cesarean section, no breastfeeding, family history of asthma, rhinitis, eczema, pets, high density of road traffic, meat, margarine, fast food, paracetamol use, and antibiotic use.

Conclusion: Childhood asthma is common, and the prevalence of asthma is highest in Oceania, with a lower prevalence in Eurasia. Moreover, the risk factors for childhood asthma were comprehensively identified, and health education should be provided to prevent modifiable factors.