title: Data linkage to estimate the extent and distribution of occupational disease: new onset adult asthma in Alberta, Canada.
abstract: BACKGROUND
  Although occupational asthma is a well recognized and preventable disease, the numbers of cases presenting for compensation may be far lower than the true incidence.
  
  
  METHODS
  Workers' Compensation Board (WCB) claims for any reason 1995-2004 were linked to physician billing data. New onset adult asthma (NOAA) was defined as a billing for asthma (ICD-9 code of 493) in the 12 months prior to a WCB claim without asthma in the previous 3 years. Incidence was calculated by occupation, industry and, in a case-referent analysis, exposures estimated from an asthma specific job exposure matrix.
  
  
  RESULTS
  There were 782,908 WCB eligible claims, with an incidence rate for NOAA of 1.6%: 23 occupations and 21 industries had a significantly increased risk. Isocyanates (OR 1.54: 95% CI 1.01-2.36) and exposure to mixed agricultural allergens (OR = 1.59: 95% CI 1.17-2.18) were related to NOAA overall, as were exposures to cleaning chemicals in men (OR = 1.91:95% CI 1.34-2.73). Estimates of the number of cases of occupational asthma suggested a range of 4% to about half for the proportion compensated.
  
  
  CONCLUSIONS
  Data linkage of administrative records can demonstrate under-reporting of occupational asthma and indicate areas for prevention.
authors.affiliation: Department of Medicine, University of Alberta, Alberta, Canada. ncherry@ualberta.ca
authors.forename: Nicola
authors.initials: N
authors.lastname: Cherry
authors.forename: Jeremy
authors.initials: J
authors.lastname: Beach
authors.forename: Igor
authors.initials: I
authors.lastname: Burstyn
authors.forename: Xiangning
authors.initials: X
authors.lastname: Fan
authors.forename: Na
authors.initials: N
authors.lastname: Guo
authors.forename: Nitin
authors.initials: N
authors.lastname: Kapur
mesh_terms: D000328:Adult; D017668:Age of Onset; D000416:Alberta / Q000453:epidemiology; D001249:Asthma / Q000453:epidemiology* / Q000517:prevention & control; D016022:Case-Control Studies; D003625:Data Collection; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009784:Occupational Diseases / Q000453:epidemiology* / Q000517:prevention & control; D014942:Workers' Compensation / Q000706:statistics & numerical data*