title: [Risk factors on chronic obstructive pulmonary disease among greenhouse workers in Liaoning province].
abstract: OBJECTIVE
  To study the risk factors of chronic obstructive pulmonary disease (COPD) among greenhouse farmers in Liaoning province.
  
  
  METHODS
  According to geographical differences in Liaoning province, stratified-cluster-random sampling method was used. A total of 5420 greenhouse farmers working in more than 800 greenhouses were investigated with unified questionnaire, physical examination, blood routine examination, blood gas analysis, chest X-ray and pulmonary function tests. Diagnosis of COPD was made according to the criteria for "chronic obstructive pulmonary disease of diagnosis and treatment guidelines" (2007 revision) by the Chinese Respiratory Disease Society.
  
  
  RESULTS
  The total number of farmers under study was 5880, including 5420 respondants (92.18%) with effective data. Risk factors were found on age (χ2=32.530, P=0.000), time working in greenhouses every day (χ2=21.311, P=0.000), frequency of ventilation (χ2=9.791, P=0.007) and the location of the greenhouses (χ2=73.645, P=0.000). When using SPSS 17.0 for the single factor logistic regression analysis, results indicated that smoking (OR=1.976, 95%CI: 1.672 - 2.334), age (OR=4.188, 95%CI: 3.718-4.718), greenhouses for fungus (compared with vegetables, OR=1.302, 95%CI: 1.016-1.669), flowers and plants (compared with vegetables greenhouses, OR=1.503, 95%CI: 1.201-1.880) were the risk factors of COPD among greenhouse farmers while the protective factor was the years of working in the greenhouse (OR=0.684, 95%CI: 0.609-0.767).
  
  
  CONCLUSIONS
  The overall morbidity of COPD among greenhouse farmers in Liaoning province was 17.47% with various risk factors.
authors.affiliation: Department of Respiratory Diseases, the Fourth Affiliated Hospital of China Medical University, Shenyang 110032, China.
authors.forename: Shuo
authors.initials: S
authors.lastname: Liu
authors.forename: Li-yun
authors.initials: LY
authors.lastname: Li
authors.forename: Zhen-hua
authors.initials: ZH
authors.lastname: Li
authors.forename: De-liang
authors.initials: DL
authors.lastname: Wen
authors.forename: Xiao-ge
authors.initials: XG
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000383:Agriculture; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology*; D012307:Risk Factors; D011795:Surveys and Questionnaires; D055815:Young Adult