Characteristics of ASAS peripheral SpA patients across regions.
| Variables | Japan | Asia | Non-Asia | p |
|---|---|---|---|---|
| N | 42 | 67 | 449 | |
| Age at enrollment, yrs, mean (SD) | 53.3 (14.6) | 38.8 (14.2) | 50.2 (13.7) | < 0.001 |
| Age at disease onset, yrs, mean (SD) | 38.3 (16.6) | 30.0 (12.7) | 33.4 (15.4) | 0.026 |
| Age at disease diagnosis, yrs, mean (SD) | 47.8 (15.0) | 34.9 (13.8) | 41.5 (13.9) | < 0.001 |
| Female | 14 (33.3) | 19 (28.4) | 209 (46.5) | 0.008 |
| Smoking status | 0.001 | |||
| Never | 19 (45.2) | 53 (79.1) | 247 (55.0) | |
| Past | 13 (31.0) | 5 (7.5) | 131 (29.2) | |
| Current | 10 (23.8) | 9 (13.4) | 71 (15.8) | |
| BMI, mean (SD) | 23.7 (3.5) | 24.2 (4.2) | 28.4 (6.2) | < 0.001 |
| Obesity | 1 (2.4) | 7 (10.4) | 144 (33.1) | < 0.001 |
| Peripheral arthritis | 42 (100.0) | 64 (95.5) | 424 (94.4) | 0.280 |
| Enthesitis | 20 (47.6) | 35 (52.2) | 223 (49.7) | 0.886 |
| Dactylitis | 20 (47.6) | 20 (29.9) | 171 (38.1) | 0.171 |
| Uveitis | 3 (7.1) | 9 (13.4) | 60 (13.4) | 0.511 |
| Psoriasis | 30 (71.4) | 16 (23.9) | 275 (61.2) | < 0.001 |
| CASPAR criteria | 31 (73.8) | 16 (23.9) | 275 (61.2) | < 0.001 |
| Inflammatory bowel disease | 2 (4.8) | 1 (1.5) | 19 (4.2) | 0.539 |
| Good response to NSAID | 18 (42.9) | 48 (71.6) | 245 (54.6) | 0.007 |
| HLA-B27 measured | 16 (38.1) | 59 (88.1) | 251 (55.9) | < 0.001 |
| HLA-B27 positivity among measured | 5 (31.2) | 44 (74.6) | 133 (53.0) | 0.001 |
| Swollen joint count (0–44) | 1.0 (0.0, 2.0) | 1.0 (0.0, 2.0) | 1.0 (0.0, 2.0) | 0.603 |
| Tender joint count (0–44) | 1.0 (0.0, 2.0) | 1.0 (0.0, 2.0) | 2.0 (0.0, 4.0) | 0.007 |
| ESR, mm/h, mean (SD) | 21.8 (22.1) | 26.8 (28.0) | 20.6 (20.2) | 0.114 |
| CRP | 0.2 (0.1, 1.3) | 0.5 (0.3, 1.6) | 0.7 (0.3, 2.6) | 0.011 |
| PGA (0–10) | 2.0 (1.0, 3.0) | 4.0 (2.0, 4.0) | 3.0 (2.0, 5.0) | 0.001 |
| PtGA (0–10) | 1.0 (1.0, 3.0) | 3.0 (2.0, 7.0) | 4.0 (2.0, 6.0) | < 0.001 |
| NSAID use since onset | 30 (71.4) | 61 (91.0) | 391 (87.1) | 0.009 |
| Current glucocorticoid use | 2 (4.8) | 18 (26.9) | 81 (18.0) | 0.014 |
| Conventional synthetic DMARD | 33 (78.6) | 47 (70.1) | 362 (80.6) | 0.143 |
| Methotrexate | 26 (61.9) | 24 (35.8) | 284 (63.3) | < 0.001 |
| Sulfasalazine | 16 (38.1) | 40 (59.7) | 186 (41.4) | 0.015 |
| Biological DMARD | 12 (28.6) | 19 (28.4) | 224 (49.9) | < 0.001 |
| TNF antagonists | 12 (28.6) | 19 (28.4) | 222 (49.4) | < 0.001 |
Values are expressed as n (%) or median (IQR) unless otherwise indicated. BMI: body mass index; ASAS: Assessment of Spondyloarthritis international Society; SpA: spondyloarthritis; CASPAR: ClASsification for Psoriatic ARthritis; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; PGA: physician’s global assessment; PtGA: patient’s global assessment; BASFI: Bath Ankylosing Spondylitis Functional Index; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; NSAID: nonsteroidal antiinflammatory drug; DMARD: disease-modifying antirheumatic drug; TNF: tumor necrosis factor.