Table 1. Baseline characteristics of the CSA-patients (N=241).

Patient characteristic
Age in years, mean (SD)	44 (13)
Female sex, n (%)	187 (78)
Caucasian, n (%)	224 (93)
Family history of RA, n (%)	71 (30)
Symptom duration in weeks, median (IQR)	18 (10 – 48)
Presence of morning stiffness ≥60 minutes, n (%)	80 (33)
Current smoker, n (%)	54 (22)
BMI in kg/m2, median (IQR)	26 (24 – 30)
Baseline HAQ-score, median (IQR)	0.50 (0.20 – 0.88)
68-TJC, median (IQR)	6 (3 – 10)
Increased CRP (>10 mg/L), n (%)	53 (22)
Positive for EULAR-definition for arthralgia suspicious for progression to rheumatoid arthritis[9], n (%)	178 (74)
Autoantibody status
IgM-RF-positive (>3.5 IU/mL), n (%)	51 (21)
ACPA-positive (>7 U/mL), n (%)	32 (13)
Anti-CarP positive (>2 SD), n (%)	23 (10)

Glossary:

ACPA = anti-citrullinated peptide antibody; BMI = body mass index; CRP = C-reactive protein; HAQ = Health Assessment Questionnaire; IgM-RF = immunoglobulin M rheumatoid factor; IQR = interquartile range; RA = rheumatoid arthritis; SD = standard deviation; TJC = tender joint count.