Table 4

Effect modification between smoking or opium consumption and employment as a construction worker among men

Exposure statusN
OR (95% CI)
Never smoker and never construction worker235/2304Ref
Never smoker and construction worker14/1741.1 (0.6 to 2.1)
Ever smoker and never construction worker328/8553.4 (2.6 to 4.5)
Ever smoker and ever construction worker81/1414.8 (3.2 to 6.7)
 P value multiplicative interaction0.1
 RERI*1.2 (–0.4 to 2.8)
Never opium user and never construction worker313/2786Ref
Never opium user and construction worker33/2401.3 (0.8 to 2.0)
Ever opium user and never construction worker250/3734.7 (3.6 to 6.1)
Ever opium user and ever construction worker62/786.4 (4.2 to 9.6)
 P value multiplicative interaction0.3
 RERI†1.4 (–1.1 to 3.9)
  • *Adjusted OR for age categories (5-year categories) and residence (provinces).

  • †Interaction on an additive scale.

  • N, number; RERI, relative excess risk due to interaction.