Characteristics at treatment initiation of working age patients with RA
| Cohort I | Cohort II | Cohort III | Cohort IV | |
|---|---|---|---|---|
| Treatment initiation | Mono-DMARD | Combo-DMARD | Biological agents (RA <5 years) | Biological agents (all RA) |
| Identification source | SRQ | SRQ | SRQ/ARTIS | SRQ/ARTIS |
| N | 2796 | 973 | 1600 | 4787 |
| Women (n (%)) | 2051 (73%) | 711 (73%) | 1194 (75%) | 3725 (78%) |
| Age (range 19–60 years) | ||||
| Mean (SD) | 47 (11) | 47 (11) | 46 (11) | 48 (10) |
| Median (IQR) | 49 (39–56) | 50 (39–56) | 48 (39–55) | 51 (41–56) |
| RA duration | ||||
| Mean (SD) | 0.6 (0.5) | 1.7 (1.6) | 2.3 (1.3) | 10.1 (8.9) |
| Median (IQR) | 0.5 (0.4–0.8) | 1.2 (0.8–2.0) | 2.2 (1.2–3.4) | 7.6 (3.0–14.7) |
| Median identification year | 2003 | 2004 | 2004 | 2003 |
| Clinical characteristics | ||||
| HAQ | 1.0 (0.6) | 0.9 (0.6) | 1.1 (0.6) | 1.2 (0.6) |
| <1.00 | 47% | 55% | 35% | 28% |
| 1.00–1.49 | 27% | 27% | 29% | 28% |
| 1.50–1.99 | 14% | 11% | 17% | 19% |
| ≥2.00 | 7% | 3% | 8% | 13% |
| Missing | 6% | 4% | 11% | 12% |
| DAS28 | 5.0 (1.4) | 4.4 (1.3) | 5.3 (1.3) | 5.4 (1.3) |
| ≤3.2 (%) | 10 | 17 | 5 | 4 |
| 3.3–5.1 (%) | 37 | 46 | 34 | 31 |
| >5.1 (%) | 46 | 30 | 49 | 50 |
| Missing (%) | 8 | 7 | 12 | 15 |
| Tender joint count | 7.6 (6.0) | 5.7 (5.2) | 8.9 (6.5) | 8.8 (6.6) |
| Swollen joint count | 8.2 (5.5) | 5.9 (4.9) | 8.7 (5.7) | 9.2 (5.9) |
| C-reactive protein (median (IQR)) | 11 (7–27) | 10 (6–22) | 14 (7–36) | 17 (8–38) |
| Erythrocyte sedimentation rate (median (IQR)) | 23 (12–27) | 19 (10–22) | 24 (12–36) | 26 (14–38) |
| Pain VAS | 49 (25) | 43 (24) | 56 (24) | 58 (23) |
| Registered treatment (%) | ||||
| NSAID | 54 | 51 | 58 | 58 |
| Steroids | 38 | 39 | 47 | 47 |
| DMARD (non-biological) | 100 | 100 | 82 | 76 |
| Methotrexate (% of DMARD) | 77 | 92 | 93 | 89 |
| Sulfasalazine (% of DMARD) | 18 | 69 | 10 | 10 |
| Comorbid conditions (%) | ||||
| Infection | 4 | 5 | 7 | 9 |
| COPD | 2 | 2 | 3 | 3 |
| Diabetes | 3 | 3 | 4 | 3 |
| Prosthetic joint surgery | 2 | 2 | 5 | 20 |
Values are mean (SD) unless otherwise stated. Patients in cohort III are a subset of patients in cohort IV. The presence of comorbid conditions determined via discharges from inpatient care in the National Patient Register.
ARTIS, Swedish Biologics Register (integral part of the SRQ); COPD, chronic obstructive pulmonary disease; DAS28, disease activity score using 28 joint counts; DMARD, disease-modifying antirheumatic drug; HAQ, health assessment questionnaire; NSAID, non-steroidal anti-inflammatory drugs; RA, rheumatoid arthritis; SRQ, Swedish Rheumatology Quality Register; VAS, visual analogue scale.