Table 1 Relative risk for developing rheumatoid arthritis in patients, stratified for anti-cyclic citrullinated peptide (anti-CCP) antibodies
Nonsmoking | Smoking | |||
|---|---|---|---|---|
Cases/controls | Relative risk (95% confidence interval) | Cases/controls | Relative risk (confidence interval) | |
Anti-CCP antibody-positive | ||||
HLA-shared epitope-negative | 33/41 | 1.00 | 71/49 | 1.67 (0.95–2.94) |
HLA-shared epitope-positive | 62/33 | 2.05 (1.12–3.75) | 143/21 | 7.61 (4.05–14.30) |
Anti-CCP antibody-negative | ||||
HLA-shared epitope-negative | 40/41 | 1.00 | 52/49 | 1.11 (0.63–1.95) |
HLA-shared epitope-positive | 23/33 | 0.71 (0.37–1.38) | 31/21 | 1.92 (0.98–3.77) |