Table 2.

Diagnostic accuracy of vitamin D (ng/mL) to discriminate no diabetic retinopathy (NO DR), non proliferative diabetic retinopathy (NPDR), proliferative diabetic retinopathy (PDR) using ROC curve analysis

Group	Sensitivity (95% CI)	Specificity (95% CI)	+ TPV	− PV	AUC	Z value	p value
NO DR	40.91 (20.7–63.6)	81.82 (59.7–94.7)	69.2	58.1	0.581	0.93	0.352
NPDR	68.18 (45.1–86.1)	86.36 (65.1–96.9)	83.3	73.1	0.757	3.51	< 0.001
PDR	86.36 (65.1–96.9)	81.82 (59.7–94.7)	82.6	85.7	0.91	8.17	< 0.001

+ PV positive predictive value, − PV negative predictive value, AUC area under the curve