Prevalence and Risk Factors of Asthma in Children: A Systematic Review and Meta-analysis

The present study aims to evaluate the prevalence and risk factors of asthma in children through a meta-analysis. The PubMed, Embase, Cochrane, and Web of Science databases were comprehensively retrieved for studies on the prevalence and risk factors of childhood asthma (CA) published between January 1, 2015, and July 8, 2024. Studies were screened and selected based on predefined eligibility criteria, and pertinent data were extracted. The quality of eligible studies was evaluated through the Newcastle-Ottawa Scale (NOS). Statistical analyses were undertaken via Stata 16 and R 4.4.1. 45 studies comprising 647,414 participants were included. The pooled prevalence of CA was 11.9% (95% CI: 8.8–15.8%). The meta-analysis identified several risk factors for CA, including prenatal exposure to per- and polyfluoroalkyl substances (PFAS) (OR = 0.89, 95% CI: 0.80–0.98, P = 0.021), prenatal exposure to acid-suppressive medications (OR = 1.11, 95% CI: 1.04–1.19, P = 0.002), maternal folic acid supplementation during pregnancy (OR = 1.18, 95% CI: 1.10–1.27, <i>p</i> &lt; 0.001), as well as <i>Helicobacter pylori</i> infection in childhood (OR = 2.07, 95% CI: 1.35–3.15, <i>p</i> = 0.001). The prevalence rate of asthma among children was approximately 11.9%. Prenatal exposure to PFAS and acid-suppressive medications, <i>Helicobacter pylori</i> infection in childhood were proved to be risk factors for asthma. Folic acid supplementation during pregnancy is positively associated with a reduced risk of asthma in children. Further large-scale prospective research is warranted to unveil the roles and significance of these factors.