Table 1

Demographic and clinical characteristics of the study participants

VariableAll
n=93
Population 1
n=41
Population 2
n=52
Age (years)41 (22)47 (20)37.5 (18.5)
Sex: female49 (52.7%)20 (48.8%)29 (55.8%)
Race: Caucasian64 (68.8%)
Disease status
 PsA65 (69.9%)41 (100%)24 (46.2%)
 Psoriasis+axial pain28 (30.1%)0 (0%)28 (53.9%)
PsA duration (years)*1.6 (0.9)1.7 (2.1)1.4 (1.1)
Duration of MSK symptoms (years)4 (7.9)3.4 (4.4)4.2 (8.9)
Duration of psoriasis (years)12.3 (17.7)14.7 (15.9)11.4 (18.1)
NSAIDs—daily use (y/n)6 (6.5%)2 (4.9%)4 (7.8%)
DMARDs use (y/n)22 (23.7%)12 (29.3%)10 (19.2%)
Ever smoker (y/n)36 (38.7%)12 (29.3%)24 (46.2%)
Family history of PsA or SpA (y/n)6 (6.5%)3 (7.3%)3 (5.8%)
Anterior uveitis (y/n)5 (5.4%)3 (7.3%)2 (3.9%)
Inflammatory bowel disease (y/n)2 (2.2%)1 (2.4%)1 (1.1%)
Axial symptoms (pain or stiffness) (y/n)76 (81.7%)28 (68.3%)48 (92.3%)
Inflammatory back pain (y/n)
 Rheumatologist impression53 (57%)21 (51.2%)32 (61.5%)
 Berlin criteria34 (36.6%)12 (29.3%)22 (42.3%)
 ASAS criteria34 (36.6%)10 (24.4%)24 (46.2%)
Location of axial pain (y/n)†
 Cervical35 (46.1%)13 (46.4%)22 (45.8%)
 Thoracic24 (31.6%)5 (17.9%)19 (39.6%)
 Lumbar57 (75%)18 (64.3%)39 (81.3%)
 Sacroiliac/Buttock26 (34.2%)6 (21.4%)20 (41.7%)
Peripheral joint pain (y/n)83 (89.3%)40 (97.6%)43 (82.7%)
Heel pain (y/n)31 (33.3%)14 (34.2%)17 (32.7%)
BMI (kg/m2)26.1 (7.8)25.6 (7.8)27.1 (7.5)
PASI2.5 (5.2)2.7 (6)2.5 (4.3)
Tender joint count (68 joints)2 (6)5 (9)1 (4)
Swollen joint count (66 joints)1 (4)3 (5)0 (1)
Dactylitis (y/n)15 (16.1%)12 (29.3%)3 (5.8%)
Enthesitis (y/n)44 (47.3%)27 (65.9%)17 (32.7%)
Pain score (0–10)5 (4)5 (4)4 (3.5)
PGA (0–10)5 (4)5 (4)4 (4)
BASDAI5.5 (3.3)5.9 (3.3)4.8 (3.2)
ASDAS2.4 (1.4)2.7 (1.5)2.2 (1.6)
HAQ0.4 (0.8)0.6 (0.9)0.3 (0.6)
hs-CRP (mg/L)2.1 (7.8)3.3 (10.2)1.5 (5.8)
HLA-B27 (y/n)10 (10.9%)5 (12.2%)5 (9.8%)
Erosions in peripheral joints (y/n)14 (15.4%)12 (30.8%)2 (3.9%)
  • Values are median (IQR) and frequency (%).

  • *Among patients with established diagnosis of PsA.

  • †Among those with axial pain.

  • ASAS, Assessment of Spondyloarthritis International Society; ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BMI, body mass index; DMARDs, disease-modifying antirheumatic drugs (methotrexate, sulfasalazine, leflunomide, apremilast); HAQ, Health Assessment Questionnaire; HLA-B27, human leucocyte antigen B27; hs-CRP, high-sensitivity C reactive protein; MSK, musculoskeletal; NSAIDs, non-steroidal anti-inflammatory drugs; PASI, Psoriasis Area Severity Index; PGA, patient global assessment; PsA, psoriatic arthritis; SpA, spondyloarthritis; y/n, yes/no.