Disease measures of MDA-A versus MDA-NA at baseline
| Characteristic* | Overall n=148 | MDA-A n=34 | MDA-NA n=114 | P values |
| Enthesitis, n (%) | 47 (31.8) | 7 (20.6) | 40 (35.1) | 0.11 |
| SPARCC Enthesitis Index (1–16) | 4.2 (3.1) | 2.4 (0.5) | 4.4 (3.3) | 0.20 |
| Dactylitis, n (%) | 20 (13.5) | 6 (17.6) | 14 (12.3) | 0.42 |
| Dactylitis count (1–20) | 2.4 (1.7) | 2.4 (2.6) | 2.4 (1.3) | 0.21 |
| BSA, % affected | 7.7 (13.2) | 5.6 (8.1) | 8.3 (14.4) | 0.31 |
| Physician global skin assessment, n (%) | 0.80 | |||
| Clear | 36 (24.5) | 10 (29.4) | 26 (23.0) | |
| Almost clear | 48 (32.6) | 12 (35.3) | 36 (31.9) | |
| Mild disease | 44 (29.9) | 9 (26.5) | 35 (31.0) | |
| Moderate disease | 14 (9.5) | 3 (8.8) | 11 (9.7) | |
| Severe disease | 5 (3.4) | 0 (0.0) | 5 (4.4) | |
| CDAI | 13.7 (8.2) | 12.8 (6.8) | 14.0 (8.5) | 0.44 |
| Tender joint count (68) | 6.3 (10.1) | 3.4 (5.3) | 7.2 (11) | 0.02 |
| Swollen joint count (66) | 2.7 (3.7) | 2.5 (3.5) | 2.8 (3.7) | 0.71 |
| Oligoarthritis, n (%)† | 114 (78.1) | 29 (87.9) | 85 (75.2) | 0.12 |
| BASDAI (0–10) | 4.6 (2.3) | 3.4 (2.1) | 5.0 (2.3) | 0.001 |
| BASFI (0–10) | 3.6 (2.5) | 2.0 (1.9) | 4.1 (2.4) | <0.001 |
| Spinal mobility measures | ||||
| Occiput-to-wall distance (cm) | 1.2 (2.1) | 0.9 (1.8) | 1.3 (2.3) | 0.80 |
| Lateral lumbar flexion (cm) | ||||
| Left | 16.5 (8.9) | 15.5 (8.2) | 16.9 (9.3) | 0.97 |
| Right | 16.4 (8.5) | 17.2 (5.8) | 16.1 (9.4) | 0.20 |
| DAS28-CRP | 3.2 (0.9) | 3.1 (0.9) | 3.2 (0.9) | 0.73 |
| ASDAS-CRP | 2.2 (0.9) | 1.9 (0.8) | 2.2 (1.0) | 0.14 |
| CRP (mg/L) | 4.3 (10.9) | 4.9 (10.3) | 4.1 (11.1) | 0.60 |
| ESR (mm/hour) | 17.1 (15.8) | 16.0 (14.8) | 17.5 (16.1) | 0.88 |
*All values were calculated based on available data and are presented as ‘mean (SD)’ unless otherwise stated. All variables had <20% missing data except for SPARCC Enthesitis Index (n=37/47), ASDAS-CRP (n=85), CRP (n=94) and ESR (n=92).
†Oligoarthritis was defined as ≤4 swollen joints.
ASDAS-CRP, Ankylosing Spondylitis Disease Activity Score using C-reactive protein; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; BSA, body surface area; CDAI, Clinical Disease Activity Index; CRP, C-reactive protein; DAS28-CRP, Disease Activity Score in 28 joints using C-reactive protein; ESR, erythrocyte sedimentation rate; MDA, minimal disease activity; MDA-A, minimal disease activity achievers; MDA-NA, minimal disease activity non-achievers; SPARCC, Spondyloarthritis Research Consortium of Canada; VAS, visual analogue scale.