Table 1. Baseline demographic and clinical characteristics for individuals who did not develop arthritis after follow-up and individuals who did.
| Characteristics | No arthritis N = 39 | Arthritis N = 12 | P-value |
|---|---|---|---|
| Sex, female (n (%)) | 27 (69) | 8 (67) | 0.868 |
| Age, years (median (IQR)) | 48 (35–53) | 48 (42–56) | 0.386 |
| CRP, mg/L (median (IQR)) | 2.0 (1.0–5.7) | 3.4 (1.3–11.0) | 0.208 |
| ESR, mm/hr (median (IQR)) | 9 (2–15) | 7 (5–14) | 0.678 |
| Patient VAS pain, mm (median (IQR)) | 28 (4–66) | 52 (10–78) | 0.298 |
| TJC-68 (median (IQR)) | 2 (0–6) | 2 (0–8) | 0.856 |
| Arthralgia present (n (%)) | 36 (92) | 11 (92) | 0.943 |
| SJC-66 (median (IQR)) | 0 | 0 | 1.000 |
| IgM-RF + (n (%)) | 21 (54) | 8 (67) | 0.433 |
| ACPA + (n (%)) | 24 (62) | 9 (75) | 0.393 |
| IgM-RF and ACPA + (n (%)) | 6 (15) | 5 (42) | 0.053 |
| Smoking history, ever (n (%)) | 23 (59) | 11 (92) | 0.036 |
| BMI (median (IQR)) | 24.6 (22.8–28.6) | 27.6 (24.9–29.7) | 0.053 |
| BMI ≥25 kg/m2 (n (%)) | 18 (46) | 9 (75) | 0.083 |
Parameters are described as number (n (%)) or median (interquartile range, IQR) as appropiate. CRP = C-reactive protein; ESR = erythrocyte sedimentation rate; VAS = visual analogue scale; TJC = tender joint count; SJC = swollen joint count; IgM-RF = immunoglobulin M rheumatoid factor; ACPA = anti-citrullinated protein antibody; Smoking history = never smoked: 0 pack-years; ever smoked: >0 pack-years; BMI = body mass index; P-values < 0.05 in bold.