Characteristics of patients in ESPOIR cohort included in this study of MTX use at baseline (n=288)
| Characteristic | Optimal MTX dose* (n=76) | Non-optimal MTX dose (n=212) | p |
| Age (years) | 44.5±12.6 | 50.3±11.3 | 0.0008 |
| Female sex, n (%) | 56 (73.7%) | 163 (76.9%) | 0.57 |
| Symptom duration (months)† | 8.8±9.7 | 7.7±9.2 | 0.20 |
| Smoking | 31 (40.8%) | 104 (49.1%) | 0.22 |
| DAS28 | 5.3±1.3 | 5.5±1.2 | 0.057 |
| SJC | 7.5±5.7 | 8.8±5.7 | 0.04 |
| TJC | 7.8±6.7 | 10.5±7.4 | 0.0025 |
| HAQ | 1.1±0.7 | 1.06±0.7 | 0.63 |
| C-reactive protein level‡ | 28.2±46.8 | 21.0±29.5 | 0.02 |
| Rheumatoid factor positivity, n (%)‡ | 49 (64.5%) | 131 (61.8%) | 0.68 |
| Anti-CCP2 antibodies positivity, n (%)‡ | 48 (63.2%) | 116 (54.7%) | 0.20 |
| Erosions present | 24 (33.3%) | 92 (45.1%) | 0.82 |
| SHS score | 5.9±8.3 | 5.7±7.3 | 0.75 |
| 1987 ACR criteria | 57 (75%) | 190 (89.6%) | 0.0017 |
| Use of corticosteroids in the first year§ | 10 (13.5%) | 34 (16.2%) | 0.58 |
| Use of corticosteroids during the second year¶ | 4 (5.71%) | 33 (17.01%) | 0.0255 |
| Combination with synthetic DMARDs | 19 (25%) | 22 (10.4%) | 0.0035 |
| Use of biological DMARDs | |||
| During the first year | 9 (11.8%) | 16 (7.6%) | 0.25 |
| During the first 2 years | 11 (14.5%) | 30 (14.2%) | 0.95 |
| MTX dose | |||
| At initiation (mg/week) | 14.90±4.48 | 11.18±3.12 | <0.0001 |
| At 6 months (mg/week) | 15.09±4.42 | 11.68±3.13 | <0.0001 |
| Escalation between 6 and 12 months | 11 (14.47%) | 52 (24.53%) | 0.069 |
| Folic acid supplementation at 6 months | 48 (63.16%) | 104 (49.06%) | 0.0346 |
Data are mean±SD or n (%). Significant results are in bold type.
*Optimal MTX dose defined as fulfilling the following three criteria: (1) MTX introduction during the first 3 months after inclusion in the ESPOIR cohort; (2) initial dosage ≥10 mg/week; and (3) achieving ≥20 mg/week or 0.3 mg/kg/week MTX with DAS28 >2.6 at 6 months (or any dose with DAS28 <2.6 at 6 months).
†Symptom duration defined from the appearance of the first fixed swollen joint.
‡Baseline C-reactive protein level (normal <10 mg/L); IgM and IgA rheumatoid factor (ELISA, Menarini, France; positive >9 UI/mL) and anti-CCP2 antibodies (ELISA, DiaSorin, France; positive >50 U/mL) were detected in all patients by using the same technique in a central lab (Paris-Bichat).
§At least 7.5 mg/day equivalent prednisone for more than 3 months in the first year.
¶At least 7.5 mg/day equivalent prednisone for more than 3 months in the second year.
ACR, American College of Rheumatology; DAS28, Disease Activity Score in 28 joints; DMARD, disease-modifying antirheumatic drugs; HAQ, Health Assessment Questionnaire; MTX, methotrexate; SHS, Sharp/van der Heijde score; SJC, swollen joint count; TJC, tender joint count.