Table 1– Selected baseline characteristics of participants at diagnosis
Subjects n60
 Male45 (75)
 Female15 (25)
Age yrs42.9±11.0
Atopy#42 (70)
Smoking habit
 Nonsmoker10 (16)
 Ex-smoker25 (42)
 Smoker25 (42)
Duration of exposure to causal agent yrs10.5 (3.1–22.8)
Years of exposure with symptoms before removal from exposure1.4 (0.1–7.5)
Married32 (53)
Having children to support40 (67)
Nature of causal agent
 High molecular weight26 (43)
 Low molecular weight33 (55)
Salary (<30,000 CAD)24 (40)
Low income9 (15)
Only primary and secondary level education33 (55)
Working for a company with <20 employees at diagnosis20 (33)
Working ≥5 yrs for same employer34 (57)
Member of a labour union28 (47)
Professional group
 Shopkeepers, craftsmen23 (38)
 Professionals, managers, intermediate white collars, office and sales employees11 (18)
 Skilled and unskilled workers26 (43)
  • Data are presented as n (%), mean±sd or median (interquartile range), unless otherwise stated. #: atopy was defined by at least one immediate skin reaction to 15 ubiquitous aeroallergens; : low income was defined as having an income at diagnosis that was <110% of the cut-off value for low income according to the definition adopted by Statistics Canada (Ottawa, ON, Canada).