Exacerbations of COPD and symptoms of gastroesophageal reflux: a systematic review and meta-analysis

Objective: To examine the relationship between gastroesophageal reflux (GER) and COPD exacerbations. Methods: We conducted a systematic search of various electronic databases for articles published up through December of 2012. Studies considered eligible for inclusion were those dealing with COPD, COPD exacerbations, and GER; comparing at least two groups (COPD vs. controls or GER vs. controls); and describing relative risks (RRs) and prevalence ratios-or ORs and their respective 95% CIs (or presenting enough data to allow further calculations) for the association between GER and COPD-as well as exacerbation rates. Using a standardized form, we extracted data related to the study design; criteria for GER diagnosis; age, gender, and number of participants; randomization method; severity scores; methods of evaluating GER symptoms; criteria for defining exacerbations; exacerbation rates (hospitalizations, ER visits, unscheduled clinic visits, prednisone use, and antibiotic use); GER symptoms in COPD group vs. controls; mean number of COPD exacerbations (with symptoms vs. without symptoms); annual frequency of exacerbations; GER treatment; and severity of airflow obstruction. Results: Overall, GER was clearly identified as a risk factor for COPD exacerbations (RR = 7.57; 95% CI: 3.84-14.94), with an increased mean number of exacerbations per year (mean difference: 0.79; 95% CI: 0.22-1.36). The prevalence of GER was significantly higher in patients with COPD than in those without (RR = 13.06; 95% CI: 3.64-46.87; p < 0.001). Conclusions: GER is a risk factor for COPD exacerbations. The role of GER in COPD management should be studied in greater detail.