Table 3

OR with 95% CI of developing rheumatoid arthritis (RA) for subjects exposed to passive smoking compared with those who have never been exposed, by duration of exposure

Duration of exposure to passive smoking (years)ACPA-positive RAACPA-negative RA
ca/coOR (95% CI)*ca/coOR (95% CI)*
0205/8971.0 (reference)108/8971.0 (reference)
1–952/2211.0 (0.7–1.5)18/2210.7 (0.4–1.2)
10–1966/3191.0 (0.7–1.3)33/3190.9 (0.6–1.3)
20-616/3250.9 (0.7–1.3)45/3251.1 (0.7–1.6)
P values for trend0.80.8
  • All subjects were never-smokers.

  • *Adjusted for age, gender, residential area and ancestry.

  • ACPA, anti-cyclic citrullinated peptide antibodies; ca/co, number of exposed cases and control.