Interobserver Agreement in Magnetic Resonance of the Sacroiliac Joints in Patients with Spondyloarthritis

Table 1

Characteristics of the study population.

	ESSG			ASAS
	AS	ReA	uSpA	axSpA	pSpA
	(: 20; 30.5%)	(: 35; 52.5%)	(: 11; 16.9%)	(: 50; 76.3%)	(: 55; 83.1%)
Age of onset, years (mean; SD)
Sex (%)
Male	12 (60.0)	28 (80.0)	5 (44.0)	24 (47.6)	26 (46.9)
Female	8 (40.0)	7 (20.0)	6 (56.0)	26 (52.4)	29 (53.1)
HLA-B27 (%)	16 (82.3)	21 (61.5)	5 (48.9)	38 (75.2)	36 (65.3)
Symptom duration (median; interquartile range)	6.2 (1.4–12.1)	1.17 (0.2–4.9)	3.0 (1.4–10.1)	3.79 (1–11.6)	3.0 (1–10.7)
ESR (mean; SD)
hsCRP (median; interquartile range)	0.54 (0.2–4.1)	2.48 (0.2–15.9)	0.38 (0.1–0.5)	0.50 (0.1–2.7)	0.50 (0.2–2.4)
BASDAI (mean; SD)
BASFI (mean; SD)

ESSG: European Spondyloarthropathy Study Group; ASAS: Assessment of SpondyloArthritis International Society; AS: Ankylosing Spondylitis; ReA: Reactive Arthritis; uSpA: Undifferentiated Spondyloarthritis; axSpA: axial spondyloarthritis; pSpA: peripheral spondyloarthritis; SD: standard deviation; ESR: erythrocyte sedimentation rate; hsCRP: high sensitivity C-reactive protein; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; BASFI: Bath Ankylosing Spondylitis Functional Index.