Table 1. Baseline characteristics of patients that fulfilled the EULAR definition of arthralgia suspicious for progression to RA.

	Patients (n=325)
Female gender, n (%)	239 (74)
Age, mean (SD)	44 (13)
Symptom duration weeks, median (IQR)	18 (9–33)
Pain at joint level -68-TJC assessed at physical examination -patient-reported pain (68 joints)*	6 (3–12) 18 (10–31)
Pain in small imaged joints, median (IQR)† -joint tenderness at physical examination -patient-reported pain*	1 (0–2) 3 (1–4)
VAS-pain, mean (SD)	5.2 (2.1)
ESR, median (IQR)	2 (0–9)
ACPA-positive, n (%)	35 (11)
RF-positive, n (%)	59 (18)
ACPA and/or RF-positive, n (%)	66 (20)
MRI-detected features, median (IQR)
Total synovitis score	1 (0–3)
Total BME score	1 (0–2)
Total tenosynovitis score	0 (0–1.5)
Total inflammation score	2.5 (1.5–6)

^*In May 2015 a patient-reported joint count (assessing 68 joints) was added to the CSA-protocol and was collected in 156 consecutive patients.

^†The imaged joints were 4 MCP-joints and 1 wrist per patient, thus 5 joints in total. Missings were as follows: VAS-pain (20), ACPA (2), RF (3), 68-TJC (1), Patient-reported joint pain (169)

SD, standard deviation; IQR, interquartile range; 68-TJC, tender joint count; VAS, visual analogue scale; ESR, erythrocyte sedimentation rate; ACPA, anticitrullinated protein antibody; RF, rheumatoid factor; MRI, magnetic resonance imaging; BME, bone marrow edema; CSA, clinically suspect arthralgia.