Table 3

HRs (95% CIs) for incident seropositive rheumatoid arthritis (RA) according to passive smoking in childhood, overall and after stratified by ever-smoking status among women in the E3N cohort (N=79 318)

Seropositive RA cases, no/person-years, noModel 1
HR (95% CI)
Model 2
HR (95% CI)
All population (N=79 318)N=210
 Passive smoking in childhood
  No169/1 634 324ReferenceReference
  Yes41/256 22631.55 (1.10 to 2.18)1.55 (1.10 to 2.18)
  P value0.0120.012
Never smokers (N=42 927)N=107
 Passive smoking in adulthood
  No87/897 762ReferenceReference
  Yes20/124 4301.66 (1.02 to 2.70)1.67 (1.03 to 2.71)
  P value0.0410.039
Ever smokers (N=36 391)N=103
 Passive smoking in adulthood
  No82/736 562ReferenceReference
  Yes21/131 8341.44 (0.89 to 2.32)1.44 (0.89 to 2.32)
  P value0.140.13
All population (N=79 318)N=210
 Never smoker, no passive smoking in childhood87/897 762ReferenceReference
 Never smoker, passive smoking in childhood20/124 4301.66 (1.02 to 2.70)1.68 (1.03 to 2.73)
 Ever smoker, no passive smoking in childhood82/736 5621.15 (0.85 to 1.56)1.15 (0.85 to 1.57)
 Ever smoker, passive smoking in childhood21/131 8341.66 (1.03 to 2.67)1.66 (1.03 to 2.69)
  • Model 1: adjusted for age (as the timescale).

  • Model 2: adjusted for age (as the timescale), active smoking status (current smoker, non-smoker, former smoker, except for stratified analyses and combined analysis), passive smoking in adulthood, body mass index (kg/m²) (<18.5 kg/m², 18.5–25 kg/m², 25–30 kg/m², ≥30 kg/m²), and educational level (<high school, up to two-level university, three/four-level university).

  • E3N, Etude Epidémiologique auprès des femmes de la Mutuelle générale de l’Education Nationale.