title: Exacerbations of COPD and symptoms of gastroesophageal reflux: a systematic review and meta-analysis.
abstract: 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.
authors.affiliation: Graduate Program in Medical Sciences, Federal University of Santa Catarina, Florianópolis, Brazil.
authors.forename: Thiago Mamôru
authors.initials: TM
authors.lastname: Sakae
authors.forename: Márcia Margaret Menezes
authors.initials: MM
authors.lastname: Pizzichini
authors.forename: Paulo José Zimermann
authors.initials: PJ
authors.lastname: Teixeira
authors.forename: Rosemeri Maurici da
authors.initials: RM
authors.lastname: Silva
authors.forename: Daisson José
authors.initials: DJ
authors.lastname: Trevisol
authors.forename: Emilio
authors.initials: E
authors.lastname: Pizzichini
mesh_terms: D018450:Disease Progression; D005260:Female; D005764:Gastroesophageal Reflux / Q000150:complications* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology* / Q000628:therapy; D012189:Retrospective Studies; D012307:Risk Factors