Table 5. Intra-observer variation weighted Cohen kappa statistics.

Measure	Treatment decisions	Plus disease	ROP stage	ROP zone
UK	0.95	0.84	0.92	0.74
ANZ	0.91	0.81	0.84	0.63
INT	0.72	0.91	0.9	0.88
All	0.88	0.85	0.88	0.83