Table 4.

Percentage of agreement (PA) and Cohen’s Kappa coefficient with 95% confidence interval for accuracy, defined as SFR classification compared with gold standard classification (GS) for all humerus fractures

	Accuracy
	SFR vs GS
	PA	Kappa (95% CI)
AO/OTA group (4 signs)	61%	0.57 (0.47-0.67)
AO/OTA type (3 signs)	75%	0.66 (0.55-0.76)

AO/OTA group – 4 signs refer to a full AO/OTA classification with 4 signs e.g. 11A1. AO/OTA type – 3 signs refer to a simplified AO/OTA classification with 3 signs only e.g. 11A