Table 5

Joint effect (HR and 95% CI)* of exposure to asbestos and smoking on lung cancer mortality in asbestos workers and controls

Non-smokingSmoking
Control cohort1.006.03 (0.75 to 48.21)
Asbestos cohort7.52 (0.90 to 62.79)17.35 (2.38 to 126.57)
 Synergy index1.4141 (0.734 to 3.987)
  Low level†2.06 (0.13 to 33.17)10.71 (1.41 to 81.58)
  Medium level6.39 (0.40 to 102.17)18.43 (2.33 to 145.88)
  High level26.15 (2.91 to 234.88)28.58 (3.82 to 213.64)

  • ↵* HR and 95% CI using Cox model, adjusting for age at entry.

  • ↵† Non-smoking controls served as reference group in comparison with asbestos workers in different exposure levels.