Table 1.
Population characteristics at baseline and comparison between cases (patients with DFR status) and their paired controls
| Study population, n = 209 | Cases, n = 23 | Controls, N = 46 | p | |
|---|---|---|---|---|
| Sociodemographic characteristics | ||||
| Years of agea | 38.3 (27.2–48.3) | 39 (25.5–44.2) | 36.3 (27.9–46.6) | 0.656 |
| Female sexb | 183 (87.6) | 18 (78.3) | 36 (78.3) | 1 |
| Years of formal educationa | 12 (9–15) | 12 (9–15) | 11.5 (9–14) | 0.5 |
| Medium-low SE statusb | 188 (90) | 20 (87) | 39 (84.8) | 1 |
| RA-related characteristics | ||||
| Months of disease durationa | 5.1 (3–6.8) | 5.2 (2.5–7) | 4.9 (2.9–7.1) | 0.775 |
| RF (positive titers)b | 173 (82.8) | 13 (56.5) | 33 (71.7) | 0.280 |
| ACPA (positive titers)b | 172 (82.3) | 11 (47.8) | 28 (60.9) | 0.318 |
| Erosionsb | 21 (10.1) | 1 (4.3) | 5 (10.9) | 0.656 |
| DAS28a | 5.8 (4.6–6.8) | 5.3 (4.5–6.4) | 5.6 (4.2–6.5) | 0.990 |
| Swollen joint counta | 13 (8–18) | 10 (6–16) | 11.5 (7.8–18) | 0.389 |
| Tender joint counta | 13 (7–18) | 12 (6–18) | 12 (7–16) | 0.784 |
| ESR, mm/Ha | 21 (10–39) | 18 (13–31) | 19 (7.5–35.3) | 0.731 |
| CRP, mg/dLa | 0.7 (0.2–2.5) | 0.3 (0.1–1.5) | 0.6 (0.2–2.4) | 0.074 |
| Patient-reported outcomes measures | ||||
| HAQ score (0–3)a | 1.4 (0.9–2) | 1.3 (0.8–1.8) | 1.1 (0.4–1.8) | 0.342 |
| SF36 physical-component score (0–100)a | 35 (23.5–54.2) | 30.7 (22.3–51.3) | 44.7 (27.3–66.6) | 0.044 |
| SF36 mental-component score (0–100)a | 44.6 (29.7–59.4) | 39.5 (28.8–66) | 51.7 (37.3–68) | 0.208 |
| Patient-overall disease-VASa | 51 (28.5–74) | 44 (18.5–68) | 44.5 (23.8–73.8) | 0.593 |
| RA-related treatment | ||||
| With corticosteroidsb | 109 (52.2) | 9 (39.1) | 18 (39.1) | 1 |
| With DMARDsb | 209 (100) | 23 (100) | 46 (100) | NA |
| DMARDs/patient | 2 (1–2) | 2 (1–2) | 2 (1–2) | 0.265 |
SE socio-economic, RF rheumatoid factor, ACPA antibodies to citrullinated proteins, DAS28 Disease Activity Score (28 joints), ESR erythrocyte sedimentation rate, CRP C-reactive protein, VAS visual analog scale, HAQ Health Assessment Questionnaire, SF-36 Short Form 36 Items, DMARDs disease-modifying anti-rheumatic drugs
aMedian (IQR)
bNumber (%) of patients