Table 2.

Extent of agreement between orthopaedic surgeon and OAI site investigators using bilateral baseline OAI knee radiographic data

Measurement	Number	κw	95% CI for κw	κw(max)
Medial joint space narrowing	225	0.73	0.60, 0.85	0.84
Lateral joint space narrowing	225	0.67	0.54, 0.80	0.76
Modified Kellgren-Lawrence grade	224	0.84	0.76, 0.91	0.94

OAI = Osteoarthritis Initiative; κ_w = weighted kappa.