Table 4.

Interobserver reproducibility of joint space width measurements

View	Observer	Baseline JSW reading 1 (mm; mean ± SD)	Mean of difference (mm; mean ± SD)	ICC (95% CI)	Joint space change from M0 to M36 in reading 1 (mm)	ICC (95% CI)
Pelvic	1	2.33 ± 0.81	-0.34 ± 0.52	0.80 (0.52–0.91)	-0.40 ± 0.65	0.79 (0.65–0.88)
	2	2.67 ± 1.07			-0.54 ± 0.66
Hip AP	1	2.41 ± 0.86	-0.27 ± 0.39	0.88 (0.66–0.95)	-0.39 ± 0.61	0.87 (0.78–0.93)
	2	2.69 ± 1.05			-0.49 ± 0.66
Oblique	1	2.37 ± 0.79	-0.31 ± 0.61	0.72 (0.50–0.85)	-0.46 ± 0.59	0.86 (0.76–0.92)
	2	2.69 ± 1.00			-0.47 ± 0.67

Shown is the interobserver reproducibility of joint space width (JSW) measurements between the two readers for the three radiographic views. AP, anteroposterior; CI, confidence interval; ICC, intraclass coefficient of correlation; SD, standard deviation.