Development of the Short-Form Yin Deficiency Scale Using Three Item Reduction Approaches

Table 8

ROC curve analyses of the three short-form YDS by Rasch, EITC, and factor-based approaches.

Rasch analysis (item numbers = 14)				EITC (item numbers = 14)				Factor analysis (item numbers = 16)
Points	Sensitivity	Specificity	Youden index	Points	Sensitivity	Specificity	Youden index	Points	Sensitivity	Specificity	Youden index
29.5	0.965	0.205	0.170	42.5	0.825	0.589	0.414	44.5	0.895	0.438	0.332
30.5	0.965	0.232	0.197	43.5	0.807	0.607	0.414	45.5	0.877	0.473	0.350
31.5	0.947	0.277	0.224	44.5	0.789	0.634	0.423	46.5	0.860	0.509	0.369
32.5	0.947	0.321	0.269	45.5	0.772	0.652	0.424	47.5	0.860	0.545	0.404
33.5	0.930	0.384	0.314	46.5	0.737	0.679	0.415	48.5	0.860	0.598	0.458
34.5	0.930	0.464	0.394	47.5	0.719	0.723	0.443	49.5	0.860	0.616	0.476
35.5	0.930	0.482	0.412	48.5	0.684	0.768	0.452	50.5	0.789	0.634	0.423
36.5	0.895	0.509	0.404	49.5	0.667	0.795	0.461	51.5	0.789	0.661	0.450
37.5	0.860	0.563	0.422	51.0	0.667	0.813	0.479	52.5	0.789	0.679	0.468
38.5	0.842	0.634	0.476	52.5	0.632	0.848	0.480	53.5	0.772	0.688	0.459
39.5	0.807	0.705	0.512	53.5	0.632	0.875	0.507	54.5	0.754	0.750	0.504
40.5	0.789	0.741	0.531	54.5	0.596	0.893	0.489	55.5	0.754	0.768	0.522
41.5	0.702	0.759	0.461	55.5	0.561	0.902	0.463	56.5	0.737	0.786	0.523
42.5	0.684	0.795	0.479	56.5	0.509	0.902	0.411	57.5	0.684	0.813	0.497
43.5	0.596	0.848	0.445	57.5	0.491	0.920	0.411	58.5	0.649	0.830	0.479
44.5	0.509	0.866	0.375	58.5	0.439	0.929	0.367	59.5	0.632	0.848	0.480
45.5	0.439	0.902	0.340	59.5	0.421	0.955	0.376	60.5	0.614	0.848	0.462
46.5	0.368	0.946	0.315	60.5	0.351	0.955	0.306	61.5	0.579	0.857	0.436

ROC, receiver operating characteristic; YDS, Yin Deficiency Scale; EITC, equidiscriminatory item-total correlation. The values in bold indicate maximum Youden indexes (sensitivity + specificity− 1) obtained using ROC curve analyses and cut-off points corresponding to the Youden indexes.