A systematic review and meta-analysis exploring the bidirectional association between asthma and gastroesophageal reflux disease in children.

Background: Asthma is the most prevalent chronic respiratory disease in children, and gastroesophageal reflux disease (GERD) is one of its extraesophageal complications of asthma. Both conditions are commonly observed in pediatric outpatient clinics, but the causality between them in children is still debated. Therefore, we conducted a systematic review and meta-analysis to evaluate the bidirectional association between asthma and GERD in children. Methods: We systematically reviewed original studies published from January 2000 to February 2024 by searching the data bases. We also performed manual retrieval and screening to identify studies that met the inclusion criteria. The quality of the final included studies was evaluated by using the Newcastle-Ottawa Scale, and outcome measures were extracted. Results: We identified nine eligible studies, which included 304,399 children of different ages from seven countries. Overall, the risk of developing GERD in children with asthma (odds ratio [OR] 2.16 [95% confidence interval [CI], 1.6-2.91) was higher than the risk of developing asthma in children with GERD (OR 1.55 [95% CI, 1.32-1.82]). Conclusion: Based on the available studies, it can be concluded that asthma and GERD are mutually aggravating factors in children, presenting a bidirectional association. However, the risk of developing GERD in children with asthma is higher to some extent. More large-scale and high-quality prospective cohort studies are needed in the future to provide richer evidence and more research opportunities.