Table 4

Relative risk of rheumatoid arthritis among former smokers by years since quitting and age at quitting cigarette smoking in the Swedish Mammography Cohort, 2003 to 2010

Person-years1

Cases, number1

Age-adjusted relative risk

95% CI

Multivariable relative risk2

95% CI


Never smokers

137,162

79

1.00 (ref)

1.00 (ref)

Years since quitting

1-14

23,297

20

1.45

0.88, 2.38

1.50

0.68, 3.30

≥ 15 (median 24)

35,613

39

1.85

1.25, 2.73

1.99

1.23, 3.20

Age at quitting

≤ 41 (median 32)

31,164

31

1.68

1.09, 2.59

1.94

1.18, 3.18

> 41 (median 50)

27,747

28

1.70

1.11, 2.62

2.02

1.01, 4.07


1 Numbers do not add up to the totals because of missing values. 2Adjusted for age (continuous), menopausal status (pre- or postmenopausal), parity (0, 1, 2, or ≥ 3 children), alcohol use(none, former, or current), educational level (lower than high school, high school, or university), body mass index (quartiles), and pack-years of smoking (continuous among former smokers). Ref, reference group.

Di Giuseppe et al. Arthritis Research & Therapy 2013 15:R56   doi:10.1186/ar4218

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