Table 1.
The Background Information of the Patients with Likely and Possible NeP and with Unlikely NeP.
| All | Likely and possible | Unlikely | p value | |
|---|---|---|---|---|
| n | 300 | 42 | 258 | |
| Age (years old) | 64.6±14.3 | 64.8±15.3 | 64.5±14.1 | 0.682 |
| BMI (kg/m2) | 22.6±3.8 | 23.7±3.7 | 22.4±3.8 | 0.0343 |
| <18.5(%) | 45 (15.0%) | 3 (7.14%) | 42 (16.2%) | 0.162* |
| <22 (%) | 137 (45.7%) | 12 (28.5%) | 125 (48.4%) | 0.0191* |
| <25 (%) | 223 (74.3%) | 28 (66.6%) | 195 (75.6%) | 0.253* |
| Duration (years) | 11.5±10.2 | 11.9±11.3 | 11.6±10.1 | 0.766 |
| Stage of RA (I/II/III/IV) | 87/82/37/94 | 16/9/6/11 | 71/73/31/83 | 0.47* |
| Class of RA (1/2/3/4) | 94/116/85/5 | 14/14/14/0 | 80/102/71/5 | 0.748* |
| DAS-28-ESR | 2.87±1.19 | 3.49±1.06 | 2.77±1.18 | <0.001 |
| Clinical remission (%) | 139 (46.3%) | 9 (21.4%) | 130 (50.4%) | <0.001* |
| CR or LDA (%) | 194 (64.6%) | 16 (38.1%) | 178 (69.0%) | <0.001* |
| CR or LDA or MDA | 284 (94.6%) | 39 (92.9%) | 245 (95.0%) | 0.477* |
| Pain VAS (mm) | 22.1±20.1 | 31.56±22.04 | 20.55±19.39 | 0.00161 |
| CRP (mg/dL) | 0.67±1.6 | 0.92±1.4 | 0.63±1.59 | 0.0484 |
| CRP<0.6 mg/dL | 227 (75.7%) | 26 (61.9%) | 201 (77.9%) | 0.0325 |
| ESR (mm/h) | 20.0±19.8 | 23.3±18.7 | 19.44±19.92 | 0.075 |
| MMP-3 (ng/mL) | 117.3±99.3 | 114.34±95.68 | 114.34±95.68 | 0.713 |
| Male MMP-3 (ng/mL) | 149.7±116.4 | 132.01±76.98 | 151.97±120.81 | 0.660 |
| Female MMP-3 (ng/mL) | 105.8±89.97 | 135.20±131.19 | 100.60±79.99 | 0.473 |
| Elevated MMP-3 (%) | 117 (39.0%) | 18 (42.9%) | 99 (38.4%) | 0.611* |
| PD-Q score | 6.70±5.27 | 16.23±3.54 | 5.13±3.58 | <0.001 |
| Orthopedic surgery (%) | 75 (25.0) | 13 (28.6) | 195 (75.5) | 0.567* |
| The numbers of orthopedic surgeries | 2.01±1.20 | 2.17±1.02 | 1.98±1.23 | 0.378 |
| Years after the first surgery | 9.43±6.66 | 13.00±7.66 | 8.74±6.29 | 0.0513 |
| Years after the last surgery | 6.11±4.51 | 7.58±6.02 | 5.83±4.16 | 0.425 |
| ACPA-positive(%) | 226 (75.3) | 29 (69.1) | 197 (75.5) | 0.336* |
| NSAID (%) | 127 (42.3) | 15 (35.7) | 112 (43.4) | 0.402* |
| Pregabalin (%) | 22 (7.3) | 5 (11.9) | 17 (6.5) | 0.21* |
| Opioid (%) | 28 (9.3) | 7 (16.6) | 21 (8.1) | 0.0881* |
| Tricyclic antidepressant | 0 (0) | 0 (0) | 0 (0) | 1* |
| Duloxetine (%) | 0 (0) | 0 (0) | 0 (0) | 1* |
| PSL (%) | 208 (69.3) | 23 (54.8) | 183 (70.9) | 0.0477* |
| PSL dose (mg/day) | 2.68±2.76 | 2.49±2.79 | 2.71±2.76 | 0.496 |
| csDMARDs(%) | 250 (83.3) | 34 (81.0) | 216 (83.7) | 0.657* |
| bDMARDs(%) | 105 (35.0) | 14 (33.3) | 91 (35.3) | 0.863* |
BMI: body mass index, RA: rheumatoid arthritis, DAS: disease activity score, VAS: visual analogue scale, CRP: C-reactive protein, ESR: erythrocyte sedimentation rate, MMP-3: matrix metalloproteinase-3, PD-Q: painDETECT questionnaire, SD: standard deviation, ACPA: anti-citrullinated protein antibody. NSAIDs: non-steroidal anti-inflammatory drugs, MTX: methotrexate, PSL: prednisolone, csDMARDs: conventional synthetic disease-modifying antirheumatic drugs, bDMARDs: biological DMARDs
Statistical analyses were performed using the Mann-Whitney U test except for those marked with *(Fisher’s exact test); p values were evaluated using the Mann-Whitney U test†or Fisher’s exact test§.