Summary of Phase 1 results
| Variable | Comparison | Relative weight† |
|---|---|---|
| Swollen MCP joint | Present versus absent | 1.5 |
| Swollen PIP joint | Present versus absent | 1.5 |
| Swollen wrist | Present versus absent | 1.6 |
| Hand tenderness | Present versus absent | 1.8 |
| Acute-phase response | Lowly abnormal versus normal | 1.2 |
| Highly abnormal versus normal | 1.7 | |
| Serology (RF or ACPA) | Low-positive versus negative | 2.2 |
| High-positive versus negative | 3.9 |
↵† Derived from OR from the multivariate regression model, and interpreted as the increase in the odds of having RA with as opposed to without the respective feature (eg, weight of 1.5 for swelling of PIP joints means that the odds of having RA is 1.5-fold in patients with as opposed to patients without swelling of a PIP joint).
ACPA, anti-citrullinated protein antibody; MCP, metacarpophalangeal; PIP, proximal interphalangeal; RA, rheumatoid arthritis; RF, rheumatoid factor.