Intraobserver precision. Shown is the intraobserver precision, summarized using the Bland and Altman plotting method, for the assessment of changes in joint space width (JSW) between baseline (M0) and 36 months (M36) for the two readers and the three different radiographic views. A total of 50 sets of three radiographs taken at M0 and M36 were read twice by 2 readers with a 15 day interval. (a) Intraobserver reproducibility for reader 1 (M0–M36): 1, pelvic view; 2, hip anteroposterior (AP) view; 3, oblique view. (b) Intraobserver reproducibility for reader 2 (M0–M36): 1, pelvic view; 2, hip AP view; 3, oblique view.