Table 3.
Reliability of FAt Spondyloarthritis Spine Score stratified according to the time interval between MRI scans
| Time interval between MRI scans (years) |
FASSS |
Smallest detectable change |
Reliability |
|||||
|---|---|---|---|---|---|---|---|---|
|
Reader 1 |
Reader 2 |
ICCs (95% CI) |
||||||
| Baseline | Change | Baseline | Change | Baseline | Change | |||
| 0 to ≤1.0 (n = 20) |
0.7 (0.3; 0.3 to 1.0) |
21.8 (32.1) |
3.7 (6.7) |
19.7 (30.2) |
6.8 (12.8) |
4.5 |
0.96 (0.89 to 0.98) |
0.74 (0.44 to 0.89) |
| >1.0 to ≤1.5 (n = 49) |
1.3 (0.2; 1.01 to 1.5) |
18.2 (20.9) |
4.2 (8.7) |
17.3 (19.2) |
5.5 (9.5) |
3.3 |
0.88 (0.80 to 0.93) |
0.83 (0.72 to 0.90) |
| >1.5 to ≤2.0 (n = 28) |
1.9 (0.1; 1.51 to 2.0) |
28.8 (40.8) |
5.1 (14.0) |
27.0 (38.1) |
6.7 (15.5) |
4.2 |
0.98 (0.97 to 0.99) |
0.90 (0.80 to 0.95) |
| >2.0 (n = 38) | 2.6 (0.7; 2.01 to 4.9) | 23.9 (28.4) | 3.8 (11.9) | 22.4 (28.0) | 5.8 (12.6) | 3.4 | 0.97 (0.94 to 0.98) | 0.90 (0.80 to 0.95) |
Time interval presented as mean (standard deviation; range) and FAt Spondyloarthritis Spine Score (FASSS) as mean (standard deviation). CI, confidence interval; ICC, intra-class correlation coefficient; MRI, magnetic resonance imaging. FASSS baseline and change scores for Exercise 2 (n = 135 pairs of MRI scans) stratified according to the time interval between MRI scans, agreement and inter-reader reliability for these scores.