Table 4. The diagnostic power of IGFBP6, Model 1, 2, 3 in discriminating unstable carotid atherosclerotic plaque.

Variables	Cut-off	AUC (95% CI)	P	Sensitivity	Specificity
IGFBP6 (ng/mL)	≤ 142.0767	0.894 (0.810, 0.977)	< 0.001	1.000	0.655
PP (Model 1)	≤ 0.38946	0.903 (0.823, 0.982)	< 0.001	0.739	0.931
PP (Model 2)	≤ 0.54239	0.906 (0.821, 0.990)	< 0.001	0.870	0.828
PP (Model 3)	≤ 0.49497	0.952 (0.900, 1.000)	< 0.001	0.913	0.897

Model 1, IGFBP6 adjusted for age, gender; Model 2, age, gender, smoke, hypertension, weight, diabetes, creatinine, tyglyceride, total-, HDL- and LDL-cholesterol levels; Model 3, IGFBP6 adjusted for all the above cofounders. IGFBP6, insulin-like growth factor binding protein 6; PP, predicted probability; AUC , the area under the curve. HDL, high density lipoprotein; LDL, low density lipoprotein.