title: Chronic obstructive pulmonary disease and mortality from pneumonia: meta-analysis.
abstract: BACKGROUND
  We aimed to determine whether patients with concomitant community-acquired pneumonia (CAP) and chronic obstructive pulmonary disease (COPD) are at greater risk of death when compared with those with CAP or acute COPD exacerbation alone. We also assessed the effect of inhaled corticosteroids (ICS) on pneumonia mortality in COPD.
  
  
  METHODS
  We searched MEDLINE and EMBASE from inception to March 2012 for studies reporting on mortality in patients with COPD and CAP. We assessed ascertainment of disease, mortality, drug exposure and adjustment for confounders. Data were pooled using random effects meta-analysis, and heterogeneity was estimated using I².
  
  
  RESULTS
  We identified 24 eligible articles overall. Evaluation of 13 studies revealed considerable heterogeneity and a non-significant mortality risk associated with concomitant COPD and CAP as compared with CAP in five studies that reported adjusted or severity-matched data, pooled RR 1.44 (95% CI 0.97-2.16, I² = 50%). There was also considerable inconsistency amongst the effect estimates from five studies that reported on the associated mortality with concomitant CAP and COPD as compared with acute COPD exacerbations alone. Evaluation of six datasets found that ICS use in COPD was not consistently associated with lower mortality in CAP. Reports of reduced mortality with prior ICS use stemmed from three studies that enrolled participants from the same healthcare database.
  
  
  CONCLUSIONS
  Evidence on associated mortality risk with concomitant CAP and COPD (as opposed to CAP alone, or COPD exacerbation alone) is weak and heterogeneous. ICS use was not consistently associated with reduced mortality from pneumonia.
authors.affiliation: Norwich Medical School, University of East Anglia, Norwich, UK. y.loke@uea.ac.uk
authors.forename: Y K
authors.initials: YK
authors.lastname: Loke
authors.forename: C S
authors.initials: CS
authors.lastname: Kwok
authors.forename: J M
authors.initials: JM
authors.lastname: Wong
authors.forename: P
authors.initials: P
authors.lastname: Sankaran
authors.forename: P K
authors.initials: PK
authors.lastname: Myint
mesh_terms: D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D017714:Community-Acquired Infections / Q000150:complications / Q000188:drug therapy / Q000401:mortality; D005260:Female; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000150:complications* / Q000188:drug therapy / Q000401:mortality; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000209:etiology* / Q000401:mortality; D019141:Respiratory System Agents / Q000008:administration & dosage; D012307:Risk Factors
chemical_list: D005938:Glucocorticoids; D019141:Respiratory System Agents