Table 2

Odds ratios of developing RA overall, ACPA-positive RA, and ACPA-negative RA among ever-smokers compared with never-smokers in MyEIRA

All

Men

Women

Ca/Co

OR (95% CI)

Ca/Co

OR (95% CI)

Ca/Co

OR (95% CI)

All RA

Never-smokers

927/1,260

1.0

61/101

1.0

866/1,159

1.0

Ever-smokers

79/65

2.2 (1.2 to 3.9)

70/60

2.0 (1.0 to 4.0)

9/5

1.9 (0.9 to 6.1)

ACPA-positive RA

Never-smokers

577/1,260

1.0

33/101

1.0

544/1,159

1.0

Ever-smokers

64/65

4.1 (1.9 to 9.2)

56/60

3.5 (1.3 to 9.4)

8/5

3.6 (0.7 to 18.4)

ACPA-negative RA

Never-smokers

350/1,260

1.0

28/101

1.0

322/1,159

1.0

Ever-smokers

15/65

0.7 (0.3 to 2.0)

14/60

0.8 (0.2 to 3.4)

1/5

0.5 (0.05 to 4.7)

ACPA, anti-cyclic citrullinated proteins antibody; Ca/Co is number of exposed cases/number of exposed controls; MyEIRA, Malaysian Epidemiological Investigation of Rheumatoid Arthritis; OR (95% CI), odds ratio and 95% confidence interval, adjusted for ethnicity and formal education by using conditional logistic regression; RA, rheumatoid arthritis.

Too et al. Arthritis Research & Therapy 2012 14:R89   doi:10.1186/ar3813