Table 1.

Baseline characteristics of the patients in the study

	RA (n = 253)	Non-RA (n = 173)
Age in years, mean ± standard deviation	62 ± 12	50 ± 14
Percentage of patients who are women	64	55
ACPA-positive, number (percentage)	143 (61.9%)	9 (5.6%)
RF-positive, number (percentage)	169 (72.5%)	27 (15.9%)
Duration of symptoms in weeks, median (range)	20 (3-52)	15 (2-52)

Percentages exclude missing data.

ACPA, anti-citrullinated protein antibody; Non-RA, other arthropathies; RA, rheumatoid arthritis; RF, IgM rheumatoid factor.