Assessment of construct validity of the VASBI: Correlation between measures (BASFI, BASMI, mSASSS) and patient VASBI score.
| Patient VASBI Score | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | Spearman | |||||
| Variable | Mean (n, %) | SD | Mean (n, %) | SD | Mean (n, %) | SD | Mean (n, %) | SD | Correlation (r) |
| BASFI1 | 1.92 (53, 17.7) | 2.303 | 3.83 (156, 52.0) | 3.031 | 5.43 (44, 14.7) | 1.00 (2, 0.7) | 0.000 | 0.338 | |
| BASFI2 | 2.57 (53, 17.7) | 2.798 | 5.03 (157, 52.3) | 3.154 | 7.18 (44, 14.7) | 3.075 | 5.00 (2, 0.7) | 4.243 | 0.419 |
| BASFI8 | 3.13 (53, 17.7) | 2.929 | 6.30 (156, 52.0) | 2.935 | 8.27 (44, 14.7) | 2.415 | 5.00 (2, 0.7) | 1.414 | 0.473 |
| BASFI | 2.506 (53, 17.7) | 2.0233 | 4.724 (157, 52.3) | 2.3065 | 6.754 (44, 14.7) | 2.0736 | 2.90 (2, 0.7) | 1.4142 | 0.490 |
| Tragwall | 11.02 (22, 7.3) | 1.635 | 16.10 (58, 19.3) | 5.347 | 21.12 (20, 6.7) | 7.577 | 0.517 | ||
| Lumflex | 6.18 (22, 7.3) | 2.015 | 4.34 (59, 19.7) | 2.047 | 3.89 (20, 6.7) | 2.429 | −0.361 | ||
| Lumside | 17.05 (22, 7.3) | 4.958 | 10.77 (59, 19.7) | 5.187 | 8.36 (20, 6.7) | 4.732 | −0.484 | ||
| Cerv | 69.36 (22, 7.3) | 18.986 | 55.17 (58, 19.3) | 23.438 | 37.48 (20, 6.7) | 17.833 | −0.438 | ||
| Intmal | 101.80 (22, 7.3) | 13.275 | 97.81 (58, 19.3) | 19.084 | 84.02 (20, 6.7) | 21.301 | −0.267 | ||
| BASMI | 1.98 (22, 7.3) | 1.225 | 3.71 (57, 19.0) | 1.737 | 5.17 (20, 6.7) | 1.617 | 0.543 | ||
| CervSC | 1.70 (17, 5.7) | 2.651 | 6.04 (44, 14.7) | 9.837 | 12.45 (14, 4.7) | 14.290 | 0.264 | ||
| LumSC | 2.13 (16, 5.3) | 4.646 | 8.02 (47, 15.7) | 12.981 | 13.71 (14, 4.7) | 16.112 | 0.218 | ||
| mSASSS | 3.93 (16, 5.3) | 6.081 | 13.79 (44, 14.7) | 19.450 | 28.18 (13, 4.3) | 26.589 | 0.309 | ||
VASBI: Visual Assessment of the Spine Bruckel Instrument; BASFI: Bath Ankylosing Spondylitis Functional Index; BASMI: Bath Ankylosing Spondylitis Metrology Index; mSASSS: modified Stoke Ankylosing Spondylitis Spine Score; BASFI1, 2, 8: questions 1, 2, 8 on BASFI; tragwall: tragus-to-wall distance; lumflex: lumbar flexion (modified Schober); lumside: lumbar side; cerv: cervical rotation; intmal: maximal intermalleolar distance; CervSC: cervical score; LumSC: lumbar score.