Table 2.

Diagnostic accuracy of RI-CRA to discriminate controls and cases using ROC curve analysis

Group	Criterion (cut off) value	Sensitivity (95% CI	Specificity (95% CI)	+PV	−PV	AUC	Z value	p value
NO DR	> 0.68	100.00 (84.4–100.0)	95.45 (77.1–99.2.)	95.7	100.0	0.999	100.69	< 0.001
NPDR	> 0.69	76.00 (54.9–90.6)	100.00 (84.4–100.0)	100.0	78.6	0.841	5.87	< 0.001
PDR	> 0.69	95.45 (77.1–99.2)	100.00 (84.4–100.0)	100.0	95.7	0.955	13.76	< 0.001
Total	> 0.69	88.41 (78.4–94.8)	100.00 (84.4–100.0)	100.0	73.3	0.928	16.22	< 0.001

+PV, positive predictive value; −PV, negative predictive value; AUC, area under the curve; NA, not applicable, NO DR no diabetic retinopathy, NPDR non proliferative diabetic retinopathy, PDR proliferative diabetic retinopathy