Table 3. Effect of low baseline VIP levels in serum on disease activity after a two-year follow-up.
| Odds ratio (95% CI) | P | |
| Age (years) | ||
| <45 | Ref. | |
| 45–65 | – | n.s. |
| >65 | – | n.s. |
| Gender | ||
| Man | Ref. | |
| Woman | 4.35 (1.46–12.99) | 0.008 |
| Diagnosis | ||
| RA | Ref. | |
| UA | – | n.s. |
| Positive RF | – | n.s. |
| Interaction VIP, ACPA | ||
| Normal VIP, ACPA-negative | Ref. | |
| Low VIP, ACPA-negative | 6.11 (1.28–29.22) | 0.023 |
| Normal VIP, ACPA-positive | 0.68 (0.24–1.9) | 0.458 |
| Low VIP, ACPA-positive | 0.24 (0.03–1.85) | 0.170 |
| DMARD treatment | ||
| None | Ref. | |
| Monotherapy | 2.2 (0.30–12.96) | 0.437 |
| Combined therapy | 6.62 (0.84–51.93) | 0.071 |
| Baseline DAS28 | – | n.s. |
| Cutpoints | β coeff. (95% CI) | |
| Remission/Low disease activity | 1.59 (–0.40 to 3.59) | – |
| Low/Moderate disease activity | 2.46 (0.44–4.49) | – |
| Moderate/High disease activity | 5.97 (3.57–8.38) | – |
DAS28∶28-joint Disease Activity Score; HAQ: Health Assessment Questionnaire; Coeff.: coefficient; Ref.: reference; RA: rheumatoid arthritis; UA: undifferentiated arthritis; ACPA: anti-citrullinated peptide antibody; n.s.: not significant.