Gastroesophageal reflux disease and asthma exacerbation: A systematic review and meta-analysis

Background Gastroesophageal reflux disease (GORD) is highly prevalent and often coexists with asthma exacerbation. Divergent findings about the association between the two diseases were reported. We conducted a systematic review and meta-analysis to determine whether there exists an association between GORD and asthma. Methods We searched MEDLINE, EMBASE, and other databases and then performed a manual search, to identify eligible studies. Pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated using fixed- and random-effect models. We evaluated the quality of included studies, explored heterogeneity between studies, undertook subgroup analyses, assessed publication bias, and performed sensitivity analyses. Results We identified 32 eligible studies, conducted in 14 countries and including a total of 1,612,361 patients of all ages. Overall, GORD shows a weak association with asthma exacerbation (OR = 1.27; 95% CI 1.18-1.35). This association was observed in cohort, case-control, and cross-sectional designs and in European as well as non-European populations. Subgroup analyses show that GORD is associated with frequent asthma exacerbations (>= 3 exacerbations, OR = 1.59; 95% CI 1.13-2.24) and with exacerbations needing oral corticosteroid therapy (OR = 1.24; 95% CI 1.09-1.41). GORD pediatric patients are at higher odds of asthma exacerbation than adults. We did not detect any evidence of publication bias and the association between GORD and asthma exacerbation held in all undertaken sensitivity analyses. Conclusions Gastroesophageal reflux disease and asthma exacerbation are weakly associated.