title: Low prevalence of asthma among textile workers in Karachi, Pakistan.
abstract: OBJECTIVE
  To determine the prevalence of asthma in textile workers through post-bronchodilator spirometry and to compare the differences in prevalence based on different criteria used to assess asthma.
  
  
  METHODS
  The cross-sectional study was conducted between July and December 2013 in Karachi, Pakistan, and comprised workers from15 textile mills in the city and its outskirts. Asthma and associated respiratory symptoms were assessed using the American Thoracic Society Division of Lung Diseases Questionnaire, and post-bronchodilator spirometry. SPSS 19 was used for statistical analysis.
  
  
  RESULTS
  Among the 372 workers in the study, asthma was found in 19(5%) as diagnosed on post-bronchodilator spirometry. The prevalence of self-reported and physician-diagnosed asthma was 15(4%) and 8(2%) respectively. Work in the spinning section, age ≥38 years, duration of work ≥10 years in textile industry, history of smoking, and ≥10 pack years of smoking were found to be important predictors of asthma.
  
  
  CONCLUSIONS
  Textile industry workers had low prevalence of asthma, assessed through post-bronchodilator spirometry, compared to estimates for the general population. This could possibly be due to some protective effect of endotoxin exposure although further evaluation with better exposure assessment is warranted.
authors.affiliation: Department of Community Health Sciences, Aga Khan University, Karachi.
authors.forename: Sana
authors.initials: S
authors.lastname: Tanzil
authors.affiliation: Department of Community Health Sciences, Aga Khan University, Karachi.
authors.forename: Asaad Ahmed
authors.initials: AA
authors.lastname: Nafees
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001249:Asthma / Q000453:epidemiology / Q000503:physiopathology; D059366:Asthma, Occupational / Q000453:epidemiology* / Q000503:physiopathology; D001993:Bronchodilator Agents; D003430:Cross-Sectional Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D010154:Pakistan / Q000453:epidemiology; D015995:Prevalence; D012907:Smoking / Q000453:epidemiology; D013147:Spirometry; D011795:Surveys and Questionnaires; D013783:Textile Industry / Q000706:statistics & numerical data*; D014797:Vital Capacity; D055815:Young Adult
chemical_list: D001993:Bronchodilator Agents
keywords: Asthma, Cotton dust, Gram-negative bacterial endotoxin, Textile workers, Pakistan.