Table 7.

Previous studies on the reliability of the classification for Legg-Calve-Perthes disease

Study	Number of subjects	Raters	Classification	Statistics
				ICC	Weighted kappa	Percentage agreement
Sambandam et al. [32]	44	2 (interobserver)	Herring		0.722
		2 (intraobserver			0.682
		2 (interobserver)	Catterall		0.443
		2 (intraobserver)			0.478
		2 (interobserver)	Salter-Thompson		0.163
		2 (intraobserver)			0.503
Agus et al. [1]	10	18 (interobserver)	Herring	0.388–0.596
		18 (intraobserver)		0.113–0.495
		18 (interobserver)	Catterall	0.578–0.620
		18 (intraobserver)		0.387–0.686
		18 (interobserver)	Salter-Thompson	0.604
		18 (intraobserver)		0.576
Herring et al. [13]	20	6 (interobserver)	Herring	0.70–0.85	0.71–0.79
		6 (intraobserver)		0.91	0.81
Akgun et al. [2]	50	3 (interobserver)	Herring		0.526–0.539
Pietrzak et al. [26]	63	3 (interobserver)	Herring		0.65–0.70
		3 (intraobserver)			0.48–0.80
		3 (interobserver)	Catterall		0.28–0.42
		3 (intraobserver)			0.43–0.61
De et al. [7]	23	9 (interobserver)	Catterall	0.94
Wiig et al. [37]	Variable (63–158)	3 (interobserver)	Herring		0.56–0.70
		3 (interobserver)	Catterall		0.49–0.62
		3 (interobserver)	Salter-Thompson		0.54–0.63
Podeszwa et al. [27]	33	5 (interobserver)	Herring		0.510
		5 (intraobserver)			0.742
Ritterbusch et al. [28]	78	3 (interobserver)	Herring			72
			Catterall			41
Simmons et al. [33]	40	15 (interobserver)	Catterall		0.49–0.64
			Salter-Thompson		0.49–0.99
Christensen et al. [6]	100	4 (interobserver)	Catterall		0.50–0.67
Hardcastle et al. [12]	69	10 (interobserver)	Catterall			30–53

ICC = intraclass correlation coefficient.