Table 2.
Characteristics of patients without (n = 418) and with (n = 301) certain diagnosis of axSpA stratified by gender
| No axSpA | p value | axSpA | p value | |||
|---|---|---|---|---|---|---|
| Male (N = 129) |
Female (N = 289) |
Male (N = 146) |
Female (N = 155) |
|||
| Age at CBP onset (years), mean (SD) | 29.3 (8.6) | 29.4 (8.2) | 0.9 | 27.4 (7.5) | 29.5 (7.8) | 0.02 |
| Duration of CBP (months), mean (SD) | 12.8 (6.9) | 13.4 (7.0) | 0.5 | 13.3 (7.1) | 13.4 (7.0) | 0.5 |
| Alternating buttock pain, n (%) (N = 454a) | 23 (43) | 100 (59) | 0.03 | 65 (60) | 64 (51) | 0.2 |
| IBP, n (%) | 83 (57) | 164 (64) | 0.2 | 123 (84) | 129 (84) | 1.0 |
| Response to NSAIDs, n (%) | 45 (37) | 81 (29) | 0.1 | 92 (64) | 98 (66) | 0.8 |
| Family history of SpA, n (%) | 44 (34) | 124 (44) | 0.1 | 68 (46) | 69 (45) | 0.8 |
| Peripheral arthritis, n (%) | 15 (12) | 25 (9) | 0.3 | 37 (25) | 34 (22) | 0.5 |
| Heel enthesitis, n (%) | 17 (13) | 28 (10) | 0.3 | 46 (31) | 51 (33) | 0.7 |
| Dactylitis, n (%) | 3 (2) | 4 (1) | 0.5 | 16 (11) | 16 (10) | 0.9 |
| Uveitis, n (%) | 7 (5) | 12 (4) | 0.6 | 19 (13) | 20 (13) | 1.0 |
| Psoriasis, n (%) | 6 (5) | 23 (8) | 0.2 | 22 (15) | 37 (24) | 0.051 |
| IBD, n (%) | 11 (8) | 15 (5) | 0.2 | 10 (7) | 12 (8) | 0.8 |
| HLA-B27+, n (%) | 43 (34) | 66 (23) | 0.02 | 114 (80) | 92 (60) | < 0.001 |
| Elevated CRP/ESR, n (%) | 21 (16) | 61 (21) | 0.2 | 71 (49) | 64 (42) | 0.2 |
| SpA features without imaging or HLA-B27, mean (SD) | 2.4 (0.1) | 2.1 (0.1) | 0.3 | 3.5 (1.7) | 3.5 (1.6) | 1.0 |
| MRI-SIJ+/X-SIJ–, n (%) | 7 (5) | 19 (6) | 0.6 | 65 (44) | 68 (44) | 0.9 |
| MRI-SIJ−/X-SIJ+, n (%) | 2 (1) | 4 (1) | 0.9 | 5 (3) | 5 (3) | 0.9 |
| MRI-SIJ+/X-SIJ+, n (%) | 5 (4) | 0 (0) | 0.01 | 44 (30) | 26 (17) | 0.006 |
| Any positive imaging,b n (%) | 14 (10) | 23 (7) | 0.3 | 114 (78) | 99 (64) | 0.007 |
| Number of syndesmophytes, mean (SD) (N = 182a) | n/a | n/a | – | 0.1 (0.4) | 0.0 (0.1) | 0.5 |
| Patients with syndesmophytes, n (%) (N = 182a) | n/a | n/a | – | 7/83 (8) | 1/99 (1) | 0.02 |
| Current smokers, n (%) | 33 (28) | 54 (19) | 0.1 | 31 (22) | 15 (10) | 0.02 |
Modified Stoke ankylosing spondylitis Spine Score available for 182/301 axSpA patients. Bold data indicate significant results
axSpA axial spondyloarthritis, CBP chronic back pain, IBP inflammatory back pain, NSAID non-steroidal anti-inflammatory drug, SpA spondyloarthritis, IBD inflammatory bowel disease, HLA human leukocyte antigen, CRP C-reactive protein, ESR erythrocyte sedimentation rate, MRI-SIJ magnetic resonance imaging of sacroiliac joints, X-SIJ plain radiograph of of sacroiliac joints
aMissing data < 5% unless otherwise indicated
bMRI-SIJ + and/or X-SIJ+