title: [Incidence of pulmonary embolism in patients with acute exacerbations of chronic obstructive pulmonary disease: a meta-analysis].
abstract: OBJECTIVE
  To evaluate the incidence of pulmonary embolism in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD).
  
  
  METHODS
  Comprehensive searches as of June 2012 were performed in PubMed (1966-), Embase (1974-), Chinese Biomedical Literature Database (1978-), Chinese Journal Full-text Database (1979-) and VIP Database (1989-) for literatures on the incidence of pulmonary embolism in patients with acute exacerbations of COPD. Meta-analysis was conducted with Stata version 11.0.
  
  
  RESULTS
  Among 2273 articles identified, 5 studies met the inclusion criteria (4 in English, 1 in Chinese). The total sample size was 762 patients, among whom 145 were diagnosed with pulmonary embolism. The incidence of pulmonary embolism ranged from 3.3% to 33.0%. Meta-analysis showed that the combined incidence was 15.8% (95%CI: 5.1%-26.4%). Among patients with acute exacerbations of COPD of unknown etiology, the incidence was 29.0% (95%CI: 20.8%-37.1%).
  
  
  CONCLUSIONS
  There is a high incidence of pulmonary embolism in patients with acute exacerbations of COPD, especially among those of an unknown etiology. More attention should be paid to this population.
authors.affiliation: Department of Respiratory Medicine, Affiliated Hospital of Medical College, Qingdao University, Qingdao 266101, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Zhao-zhong
authors.initials: ZZ
authors.lastname: Cheng
authors.forename: Jing-luan
authors.initials: JL
authors.lastname: Wang
authors.forename: Wei-zhong
authors.initials: WZ
authors.lastname: Han
authors.forename: Ni-na
authors.initials: NN
authors.lastname: Sun
mesh_terms: D006801:Humans; D015994:Incidence; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000453:epidemiology*; D011655:Pulmonary Embolism / Q000453:epidemiology* / Q000209:etiology