Table 3– 1-yr cumulative incidence and relative risk (RR) of severe exacerbation of asthma by occupation
Occupation#SubjectsSevere exacerbationRR (95% CI)
Reference+64540 (6.2)1.0 (Reference)
Healthcare§9912 (12.1)1.5 (0.95–2.4)
 Nurses§436 (14.0)1.7 (0.99–2.9)
 Other medical and pharmacy (not nurses)576 (10.5)1.3 (0.7–2.3)
Agriculture and forestry161 (6.3)
Food processing§224 (18.2)2.2 (0.97–5.0)
 Bakery workersƒ63 (50.0)7.9 (5.1–12.2)
Blue collarƒ18618 (9.7)1.4 (1.1–1.8)
 Cleaners and caretakers463 (6.5)0.8 (0.3–1.8)
 Other metal workers233 (13.0)1.6 (0.7–3.9)
 Construction and mining##193 (15.8)2.4 (0.7–7.9)
 Drivers¶¶142 (14.3)2.3 (1.03–5.0)
 Other blue collarƒ++204 (20.0)2.7 (1.4–5.1)
  • Data are presented as n or n (%), unless otherwise stated. #: a separate regression model was fit for each occupation, with white collar jobs as the common comparison group, and participants from other occupations not included in model. : RR from regression models with cluster-level variable for country, and covariates for sex, age, and smoking status. RR not calculated if fewer than two severe exacerbation cases in occupation category. +: legislators, managers, administrators, clerks and remainder professional (white collar jobs). ##: model would not converge until the continuous age variable was replaced with indicator variables based on age tertiles. ++: model would not converge until the continuous age variable was replaced with indicator variables based on age tertiles, and former and current smoking categories were combined into a single ever-smoked category. “Other blue collar” included eight “sculptors, painters, and related art,” three “protective services not elsewhere classified,” two “garbage collectors,” two “hand launderers and pressers,” and five others. §: 0.05<p≤0.10. ¶¶: p≤0.05. ƒ: p≤0.01.