Table 2.

Interobserver agreement in the diagnosis of BD

Scale	tau-b	Percentage agreement	p value
10-point	0.84	93	0.68 (ns)
7-point	0.71	89	0.50 (ns)
4-point	0.64	95	0.13 (ns)

Note: p for systematic difference between radiologists (McNemar’s test); ns not significant