|
Cohort
|
A (n=89)
|
B (n=88)
|
|---|
|
Group
|
nr-axSpA
|
AS
|
NSBP
|
HC
|
nr-axSpA
|
AS
|
NSBP
|
|---|
|
Number of subjects
|
20
|
10
|
39
|
20
|
31
|
24
|
33
|
|
Percent concordance among 10 reader pairsa
|
|
Total (positive/negative)
|
|
BME cart
|
88.0 (77.0/11.0)
|
88.0 (82.0/6.0)
|
78.5 (16.9/61.5)
|
85.0 (26.5/58.5)
|
78.1 (34.2/43.9)
|
78.3 (63.3/15.0)
|
86.7 (20.6/66.1)
|
|
BME lig
|
78.0 (31.0/47.0)
|
92.0 (76.0/16.0)
|
93.8 (0.5/93.3)
|
89.0 (0.5/88.5)
|
87.7 (5.5/82.3)
|
61.7 (19.2/42.5)
|
97.0 (0.9/96.1)
|
|
Fat cart
|
69.0 (31.5/37.5)
|
64.0 (48.0/16.0)
|
74.9 (16.7/58.2)
|
74.0 (5.0/69.0)
|
76.8 (32.3/44.5)
|
70.8 (64.6/6.3)
|
76.4 (10.6/65.8)
|
|
Fat lig
|
77.0 (9.5/67.5)
|
64.0 (28.0/36.0)
|
82.1 (9.0/73.1)
|
86.0 (5.0/81.0)
|
77.4 (13.9/63.5)
|
60.8 (22.9/37.9)
|
89.1 (3.6/85.5)
|
|
Kappa value for five readers jointly (95 % CI)b
|
|
BME cart
|
0.66 (0.56–0.75)
|
0.64 (0.53–0.72)
|
|
BME lig
|
0.68 (0.55–-0.79)
|
0.37 (0.26–0.45)
|
|
Fat cart
|
0.40 (0.32–0.49)
|
0.51 (0.42–0.60)
|
|
Fat lig
|
0.36 (0.25–0.45)
|
0.39 (0.25–0.51)
|
-
aPercent concordance among 10 possible reader pairs (100 % = 10 concordant reader pairs); Total = positive and negative concordance for presence/absence of BME or fat metaplasia in the cartilaginous and ligamentous compartment of the sacroiliac joints
-
bWeighted Cohen’s kappa values for all five readers jointly
-
AS Ankylosing spondylitis, BME Bone marrow edema, Cart Cartilaginous compartment of the sacroiliac joint, CI 95 % confidence interval, Fat Fat metaplasia, HC Healthy control, Lig Ligamentous compartment of the sacroiliac joint, nr-axSpA Nonradiographic axial spondyloarthritis, NSBP Nonspecific back pain, R Reader, RP Reader pair
