| No SE | Any SE |
---|
 | Ca/Co | OR (95% CI)* | Ca/Co | OR (95% CI)* |
---|
ACPA-positive RA | Â | Â | Â | Â |
Never-smokers | 266/986 | 1.0 | 264/202 | 4.4 (3.5 to 5.6) |
Ever-smokers | 30/52 | 3.1 (1.7 to 5.7) | 33/8 | 25.6 (10.4 to 63.4) |
AP | Â | Â | Â | 0.7 (0.5 to 1.0) |
ACPA-negative RA | Â | Â | Â | Â |
Never-smokers | 254/986 | 1.0 | 65/202 | 1.1 (0.7 to 1.7) |
Ever-smokers | 10/52 | 0.6 (0.2 to 2.0) | 3/8 | 0.8 (0.1 to 4.8) |
- ACPA, anti-cyclic citrullinated proteins antibody; AP, attributable proportion due to interaction; Ca/Co, 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, formal education, age, sex, residential area, *calculated by means of unconditional logistic regression to increase power; RA, rheumatoid arthritis; SE, shared epitope.