| χ2 | OR (95% CI) | p Value | |
| Causal pathway 1: | |||
| HLA-SE and CCP | 44.57 | 3.1 (2.2–4.3) | 1.0×10−4 |
| CCP and RF | 278.71 | 24.9 (16.2–38.2) | 1.0×10−4 |
| HLA-SE and RF | 31.95 | 2.5 (1.8–3.5) | 1.0×10−4 |
| Causal pathway 2: | |||
| HLA-SE and CCP | 44.57 | 3.1 (2.2–4.3) | 1.0×10−4 |
| CCP and erosion | 58.65 | 3.8 (2.7–5.4) | 1.0×10−4 |
| HLA-SE and erosion | 12.57 | 1.8 (1.3–2.6) | 4.0×10−4 |
CCP, cyclic citrullinated peptide; HLA-SE, Human leukocyte antigen shared epitope; RF, rheumatoid factor.