Table 4– 1-yr cumulative incidence and relative risk (RR) of severe exacerbation of asthma by occupational exposure
Occupational exposure by JEMSubjects exposedSevere exacerbationRR# (95% CI)p-value for trend
 None56834 (6.0)1.0 (reference)
 Low29624 (8.1)1.3 (0.8–2.0)
 High+10216 (15.7)3.1 (1.9–5.1)
Type of DGF
 Biological dust<0.001
  None70543 (6.1)1.0 (reference)
  Low§23426 (11.1)1.7 (1.1–2.6)
  High+275 (18.5)3.6 (2.2–5.8)
 Mineral dust0.21
  None78158 (7.4)1.0 (reference)
  Low13110 (7.6)1.1 (0.5–2.1)
  High§546 (11.1)1.8 (1.02–3.2)
 Gas and fumes0.08
  None60541 (6.8)1.0 (reference)
  Low30023 (7.7)1.1 (0.8–1.6)
  High§6110 (16.4)2.5 (1.2–5.5)
  • Data are presented as n or n (%), unless otherwise stated. JEM: job-exposure matrix; DGF: dust, gas and fumes. #: from regression models with cluster-level variable for country, and covariates for sex, age, and smoking status. Regression models fit separately to determine effect of each type of DGF exposure. : based on highest exposure to biological dust, mineral dust and gas and fumes. §: p≤0.05; +: p≤0.01.