Demographic, disease characteristics and treatments in patients with pSpA stratified by gender
| Total pSpA n=433 | Male n=203 (46.8) | Female n=230 (53.2) | P value | Standardised difference | |
| Age at study visit | 44.1 (14.4) | 41.6 (15.3) | 46.3 (13.1) | <0.01 | −0.33 |
| Smoking habit (ever) | 128 (29.6) | 86 (42.6) | 42 (18.3) | <0.001 | 0.547 |
| Alcohol (ever) | 179 (41.4) | 111 (55.0) | 68 (29.6) | <0.001 | 0.532 |
| Body mass index (kg/m2) | 26.3 (5.4) | 25.9 (5.1) | 26.7 (5.6) | 0.10 | −0.149 |
| University education | 197 (45.5) | 89 (43.8) | 108 (47.0) | 0.52 | −0.064 |
| Family history of SpA | 125 (28.9) | 65 (32.0) | 60 (26.1) | 0.17 | 0.13 |
| Family history of PsO | 63 (15.9) | 31 (16.2) | 32 (15.7) | 0.89 | 0.014 |
| Diagnosis delay (years) since the first symptom | 4.3 (6.6) | 3.8 (6.1) | 4.7 (7.1) | 0.17 | −0.136 |
| Symptom duration | 10.1 (9.5) | 10.5 (10.0) | 9.7 (8.9) | 0.35 | 0.085 |
| Axial involvement according to the rheumatologist | 238 (55.0) | 124 (61.1) | 79 (38.9) | 0.02 | 0.455 |
| Inflammatory back pain (ASAS criteria) | 240 (55.4) | 126 (62.1) | 114 (49.6) | <0.05 | 0.254 |
| Sacroiliitis on imaging, n/N (%) by: | |||||
| xRay mNY criteria | 146/398 (36.7) | 83/191 (43.5) | 63/207 (30.4) | <0.01 | 0.274 |
| MRI-SIJ, ASAS def | 126/282 (44.6) | 66/135 (48.8) | 60/141 (42.6) | 0.29 | 0.125 |
| mNY criteria or ASAS def | 198/407 (48.6) | 101/192 (52.6) | 97/215 (45.1) | 0.14 | 0.15 |
| HLA-B27 positive | 197/319 (62.3) | 116/167 (69.5) | 91/149 (54.4) | <0.001 | 0.315 |
| Elevated CRP (>5 mg/L) | 297 (68.6) | 149 (74.9) | 148 (65.5) | 0.04 | 0.207 |
| CRP (mg/L) | 13.9 (25.4) | 14.9 (26.8) | 13.1 (24.0) | 0.46 | 0.014 |
| Peripheral arthritis | 410 (94.7) | 194 (95.6) | 216 (93.9) | 0.44 | 0.076 |
| Enthesitis | 248 (57.3) | 118 (58.1) | 130 (56.5) | 0.74 | 0.032 |
| Dactylitis | 100 (23.1) | 44 (21.7) | 56 (24.3) | 0.51 | −0.062 |
| Psoriasis | 64 (14.8) | 30 (14.8) | 34 (14.8) | 0.99 | 0 |
| IBD | 25 (5.8) | 7 (3.4) | 18 (7.8) | 0.05 | −0.192 |
| Uveitis | 75 (17.3) | 33 (16.3) | 42 (18.3) | 0.58 | −0.053 |
| Concomitant fibromyalgia according to: | |||||
| Treating rheumatologist | 48 (11.1) | 6 (3.0) | 42 (18.3) | <0.001 | −0.512 |
| FiRST questionnaire | 69 (17.6) | 19 (10.6) | 50 (23.7) | <0.01 | −0.353 |
| csDMARD (ever) | 384 (88.7) | 177 (87.2) | 207 (90.0) | 0.36 | −0.088 |
| bDMARD (ever) | 223 (51.5) | 107 (52.7) | 116 (50.4) | 0.64 | 0.046 |
Results are shown as absolute numbers (percentages) or mean (SD). Estimates with p<0.05 are highlighted in bold. Standardised difference scores of 0.2, 0.5 and 0.8 represent small, medium and large effect sizes, respectively.
ASAS, Assessment of SpondyloArthritis International Society; bDMARD, biological disease-modifying antirheumatic drug; CRP, C reactive protein; csDMARD, conventional synthetic disease-modifying antirheumatic drug; FiRST, Fibromyalgia Rapid Screening Tool; IBD, inflammatory bowel disease; PsO, psoriasis; pSpA, peripheral spondyloarthritis.