Table 1

Baseline demographics and criteria variables

DemographicFrequencyMissing n (%)
Age at symptom onset (mean (SD))54 (16.2)0
Female (n (%))173 (69)0
Symptom duration in weeks (median (IQR))29.6 (4.3–71.9)0
RF low positive (n (%))25 (11)28 (11)†
High positive (n (%))47 (20)
ACPA low positive (n (%))6 (3)77 (30)†
High positive (n (%))38 (20)
Joint involvement* (n (%))0
1 large joint9 (3)
2–10 large joints9 (3)
1–3 small joints41 (16)
4–10 small joints52 (20)
>10 joints149 (57)
Acute phase reactant positive (n (%))120 (52)27 (10)
CRP116 (48)
ESR9 (64)
CRP (mean (std dev))19 (35)
ESR (mean (std dev))30 (34)
Morning stiffness ≥60 min (n (%))172 (66)0
Arthritis of ≥3 joints areas (n (%))172 (66)0
Arthritis of hand joints (n (%))215 (83)0
Symmetric arthritis (n (%))183 (70)0
Rheumatoid nodules (n (%))19 (7)0
  • *Large joints were defined as shoulders, elbows, hips, knees and ankles. Small joints are defined as metocarpophalangeal joints, proximal interphalageal joints, second through fifth metatarsophalangeal joints, thumb interphalangeal joints and wrists. Distal interphalangeal joints, first carpometacarpal joints and first metatarsophalangeal joints were excluded as per the 2012 criteria.5

  • †Missing data quoted are for individual autoantibodies. 8 (2%) patients had no results for ACPA or RF.

  • ACPA, anti-citrullinated protein antibody, CRP, C reactive protein; ESR, erythrocyte sedimentation rate; RF, rheumatoid factor.