Table 3. Intra- and interobserver agreement for fracture presence, worst fracture grade, cumulative fracture grade and vertebral height loss.

Level	Outcome	measure	Agreement
			Observer	1	2	3	4
Patient	Fracture present	absolute agreement (%) *	1	88	90	86	82
			2		94	84	84
			3			90	92
			4				90
	Worst fracture grade	Absolute agreement (%) *	1	76	82	78	74
			2		88	76	80
			3			84	88
			4				84
	Cumulative fracture grade	95% Limits of Agreement **	1	±1.99	±2.69	±1.6	±2.15
			2		±1.8	±2.58	±1.7
			3			±1.8	±1.84
			4				±1.22
Vertebral	Height loss (%)	95% Limits of Agreement **	1	±5.97	±7.25	±8.26	±11.71
			2		±8.29	±9.77	±11.31
			3			±8.36	±12.53
			4				±11.75
	Fracture present	absolute agreement (%) *	1	98	98	98	97
			2		99	98	97
			3			98	97
			4				98

Bold and italic = intra-observer.

^*Percentage of absolute agreement in the first session of each observer for the interobserver and between the first and second sessions for the intraobserver.

^**The 95% limits of agreement is the range of observer variation. This indicates that differences beyond this range cannot be ascribed to observer error alone.