Table 1. Interreader intraclass correlation coefficients and average status scores according to the RAMRIS in early arthritis patients (n=441 in total) and patients with clinically suspect arthralgia (n=82).
| Patient population | Early arthritis n=215, k=2 | Early arthritis n=226, k=2 | Clinically suspect arthralgia n=82, k=2 | Clinically suspect arthralgia n=40, k=9 | |
|---|---|---|---|---|---|
| MTP-joints | |||||
|
| |||||
| BME | ICC (95%CI) | 0.91 (0.90-0.93) | 0.92 (0.90-0.94) | 0.77 (0.64-0.85) | 0.95 (0.93-0.97) |
| Median (IQR, max) | 0.5 (0-1.5; 20) | 0.5 (0-1.5; 18) | 0.0 (0-0.5; 6) | 0.1 (0.0-0.4; 5.4) | |
| Mean (SD) | 1.5 (2.6) | 1.1 (2.0) | 0.4 (0.9) | 0.4 (0.9) | |
|
| |||||
| Synovitis | ICC (95%CI) | 0.90 (0.84-0.94) | 0.92 (0.88-0.94) | 0.92 (0.87-0.95) | 0.98 (0.97-0.99) |
| Median (IQR, max) | 1.0 (0-1.5; 8) | 0.5 (0-1.5; 10) | 0.0 (0-0.5; 6) | 0.2 (0.0-0.8; 6.2) | |
| Mean (SD) | 1.3 (1.7) | 1.2 (1.7) | 0.4 (0.9) | 0.5 (1.0) | |
|
| |||||
| Tenosynovitis | ICC (95%CI) | 0.85 (0.78-0.90) | 0.80 (0.69-0.86) | 0.96 (0.93-0.97) | 0.99 (0.98-0.99) |
| Median (IQR, max) | 0.0 (0-1.5; 9) | 0.0 (0-1.5; 12) | 0.0 (0-0.0; 7.5) | 0.0 (0.0-0.1; 6.8) | |
| Mean (SD) | 1.1 (1.8) | 1.1 (1.9) | 0.2 (0.9) | 0.3 (1.1) | |
|
| |||||
| Erosions | ICC (95%CI) | 0.88 (0.84-0.91) | 0.89 (0.86-0.92) | 0.87 (0.81-0.92) | 0.96 (0.93-0.97) |
| Median (IQR, max) | 0.5 (0-1.0; 9) | 0.0 (0-1.0; 7) | 0.0 (0-0.5; 2) | 0.0 (0.0-0.7; 1.4) | |
| Mean (SD) | 0.7 (1.0) | 0.6 (0.9) | 0.2 (0.5) | 0.3 (0.5) | |
|
| |||||
| MCP-joints | |||||
|
| |||||
| BME | ICC (95%CI) | 0.60 (0.48-0.70) | 0.90 (0.82-0.93) | 0.78 (0.65-0.86) | 0.93 (0.89-0.96) |
| Median (IQR, max) | 0 (0-0.5; 7.5) | 0 (0-1; 14) | 0 (0-0; 2) | 0 (0-0; 0.9) | |
| Mean (SD) | 0.6 (1.3) | 1.0 (1.4) | 0.1 (0.4) | 0.1 (0.3) | |
|
| |||||
| Synovitis | ICC (95%CI) | 0.91 (0.88-0.94) | 0.92 (0.89-0.94) | 0.91 (0.86-0.94) | 0.99 (0.98-0.99) |
| Median (IQR, max) | 0 (0-1; 6) | 0 (0-1; 9) | 0 (0-0; 5) | 0 (0-0; 4.9) | |
| Mean (SD) | 0.9 (1.5) | 0.8 (1.4) | 0.2 (0.6) | 0.2 (0.8) | |
|
| |||||
| Tenosynovitis | ICC (95%CI) | 0.91 (0.88-0.93) | 0.91 (0.87-0.94) | 0.95 (0.92-0.97) | 0.98 (0.96-0.99) |
| Median (IQR, max) | 0 (0-2.5; 8.5) | 1.5 (0-3; 13) | 0 (0-1; 6) | 0.1 (0-1; 5.0) | |
| Mean (SD) | 1.5 (1.9) | 2.1 (2.4) | 0.8 (1.4) | 0.8 (1.3) | |
|
| |||||
| Erosions | ICC (95%CI) | 0.93 (0.91-0.95) | 0.92 (0.90-0.94) | 0.93 (0.89-0.96) | 0.97 (0.95-0.98) |
| Median (IQR, max) | 0 (0-1; 5) | 0 (0-5; 5) | 0 (0-1; 4) | 0 (0-0.9; 1.9) | |
| Mean (SD) | 0.6 (1.0) | 0.7 (0.9) | 0.5 (0.9) | 0.4 (0.6) | |
|
| |||||
| Wrist | |||||
|
| |||||
| BME | ICC (95%CI) | 0.91 (0.88-0.93) | 0.93 (0.75-0.97) | 0.93 (0.90-0.96) | 0.96 (0.94-0.98) |
| Median (IQR, max) | 1 (0-2.5; 24) | 2 (0.5-4; 27) | 0.5 (0-1.5; 11) | 0.3 (0.1-1.2; 3.4) | |
| Mean (SD) | 2.2 (3.4) | 3.6 (4.8) | 1.1 (1.7) | 0.8 (1.0) | |
|
| |||||
| Synovitis | ICC (95%CI) | 0.90 (0.87-0.92) | 0.93 (0.91-0.95) | 0.91 (0.87-0.94) | 0.96 (0.95-0.98) |
| Median (IQR, max) | 1 (0-3; 8) | 2 (0.5-3.5; 8) | 0.5 (0-1.5; 5.5) | 0.4 (0-1.1; 3.4) | |
| Mean (SD) | 1.8 (2.1) | 2.3 (2.1) | 0.9 (1.1) | 0.7 (0.9) | |
|
| |||||
| Tenosynovitis | ICC (95%CI) | 0.93 (0.91-0.95) | 0.96 (0.95-0.97) | 0.97 (0.95-0.98) | 0.99 (0.98-0.99) |
| Median (IQR, max) | 1 (0-4; 11.5) | 1.5 (0-5; 13) | 0 (0-0; 10) | 0.1 (0-0.4; 9.2) | |
| Mean (SD) | 2.5 (3.0) | 2.8 (3.3) | 0.6 (1.7) | 0.8 (2.0) | |
|
| |||||
| Erosions | ICC (95%CI) | 0.88 (0.84-0.91) | 0.94 (0.92-0.95) | 0.87 (0.79-0.92) | 0.96 (0.94-0.98) |
| Median (IQR, max) | 1.5 (0.5-3.5; 11) | 1.8 (0.5-3; 14) | 1 (0.5-2.5; 7.5) | 0.6 (0.2-2.3; 4.2) | |
| Mean (SD) | 2.2 (2.2) | 2.2 (2.2) | 1.5 (1.5) | 1.2 (1.2) | |
Results are based on a mean-rating, absolute agreement, two-way mixed effects model.
RAMRIS: Rheumatoid Arthritis Magnetic Resonance Imaging Score; n: number of patients; k: number of readers; MTP: metatarsophalangeal; MCP: metacarpophalangeal; BME: bone marrow edema; ICC: intraclass correlation coefficients; CI: confidence interval; IQR: interquartile range; SD: standard deviation.
Consecutive early arthritis patients were scored by four readers, the first 215 consecutive patients were scored by reader 1 and 2, the remaining 226 consecutive patients by reader 3 and 4. 82 consecutive patients with clinically suspect arthralgia were scored by reader 5 and 6. Of these 82 patients, 40 were randomly selected and in addition also scored by 7 other readers.