Table 1.

Baseline characteristics of patients with RA and asymptomatic volunteers in which hand and foot MRIs were performed and patients with RA in which CRP was analysed

	Patients with RA with an MRI n=188	Asymptomatic volunteers n=192	Patients with RA with CRP measurement n=1070
Age in years, mean (SD)	56 (14)	50 (16)	56 (15)
Female, n (%)	121 (64.4)	135 (70.3)	717 (67.0)
Symptom duration in weeks, median (IQR)	15.4 (7.9–29.6)	NA	18.4 (9.1–35.6)
CRP in mg/L, median (IQR)	10.0 (3.8–23.5)	NA	14.0 (6.0–33.0)
SJC, median (IQR)	6 (3–10)	NA	8 (4–13)
ACPA positivity, n (%)	102 (54.3)	NA	550 (52.6)
RF positivity, n (%)	116 (61.7)	NA	604 (56.9)
Current smokers, n (%)	50 (28.4)	17 (8.8)	271 (25.7)
Patients consuming alcohol, n (%)	121 (64.4)	135 (69.9)	621 (58.0)
Units/week, median (IQR)	6.0 (3.0–10.5)	7.0 (4.0–14.0)	6.0 (2.0–10.5)

Of patients with RA with an MRI, smoking status and SJC were missing in 12 and 18 patients, respectively. In patients with RA with a CRP measurement, smoking status, SJC, RF and ACPA status were missing in, respectively, 17, 38, 9 and 24 patients with RA.

ACPA, anticitrullinated protein antibody; CRP, C reactive protein; NA, not assessed; RA, rheumatoid arthritis; RF, rheumatoid factor; SJC, swollen joint count.