title: Trends in Occupations and Work Sectors Among Patients With Work-Related Asthma at a Canadian Tertiary Care Clinic.
abstract: BACKGROUND
  Work-related asthma (WRA) is the most common chronic occupational lung disease in the developed world. Several factors including sociodemographic status and occupation/industry increase the risks of developing WRA. In this study, we sought to identify changes in patterns and characteristics among patients with WRA over a 15-year period in an occupational lung disease clinic.
  
  
  METHODS
  We performed a retrospective analysis of patients with WRA charts at the Occupational Lung Disease Clinic of a University Hospital in Toronto, Canada. Patients were divided into two periods classified by first attendance at the clinic 2000 through 2007 and 2008 through 2015. Comparisons between the two periods included: sociodemographic characteristics, smoking status, occupations, exposures, and submitted workers' compensation claims.
  
  
  RESULTS
  Fewer occupational asthma cases were seen in the more recent period vs the earlier period (40 vs 74 cases), with a smaller reduction in work-exacerbated asthma cases (40 vs 58). The recent period included a significantly smaller proportion employed in the manufacturing industry and isocyanate-induced cases compared with the earlier period. An increased proportion were employed in health-care and education industries (primarily cleaners and teachers) in the recent period, consistent with a corresponding increased frequency of cleaning agents and dust exposures.
  
  
  CONCLUSIONS
  The changes observed in work sectors in the patients with WRA in this clinic in Toronto are consistent with reductions reported in Ontario workers' compensation claims for occupational asthma and may relate to preventive measures. Cleaners and teachers should be a focus of further intervention measures for work-related asthma.
authors.affiliation: Department of Medicine, Institute of Medical Science, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Simeon
authors.initials: S
authors.lastname: Gotzev
authors.affiliation: Department of Medicine, Institute of Medical Science, Toronto Western Hospital, University of Toronto, Toronto, ON, Canada; Department of Medicine, St Michael's Hospital, Toronto, ON, Canada.
authors.forename: Joshua C
authors.initials: JC
authors.lastname: Lipszyc
authors.affiliation: Department of Medicine, University of Toronto, Toronto, ON, Canada.
authors.forename: Dale
authors.initials: D
authors.lastname: Connor
authors.affiliation: Department of Medicine, St Michael's Hospital, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada. Electronic address: susan.tarlo@utoronto.ca.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Tarlo
mesh_terms: D000328:Adult; D000553:Ambulatory Care; D059366:Asthma, Occupational / Q000139:chemically induced / Q000453:epidemiology* / Q000503:physiopathology; D002170:Canada / Q000453:epidemiology; D060389:Construction Industry; D003902:Detergents / Q000009:adverse effects; D004391:Dust; D005260:Female; D005433:Flour / Q000009:adverse effects; D005541:Forced Expiratory Volume; D019981:Health Care Sector; D006796:Household Work; D006801:Humans; D017953:Isocyanates / Q000009:adverse effects; D008297:Male; D066192:Manufacturing Industry; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects; D009790:Occupations / Q000639:trends*; D009864:Ontario / Q000453:epidemiology; D010150:Paint / Q000009:adverse effects; D012189:Retrospective Studies; D013663:Teaching; D062606:Tertiary Care Centers; D014797:Vital Capacity; D014934:Wood / Q000009:adverse effects
chemical_list: D003902:Detergents; D004391:Dust; D017953:Isocyanates
keywords: asthma; occupational asthma; occupational lung; work-related asthma