ABPI against Colour Duplex Scan: A Screening Tool for Detection of Peripheral Arterial Disease in Low Resource Setting Approach to Validation

Table 3

Sensitivity and specificity for selected threshold levels of levels of ABPI for detecting a ≥ 50% narrowing of arterial luminal diameter anywhere in the lower limb.

Threshold levels; (ABPI)	Sensitivity	Specificity	Distance from the curve ()
0.83	73.9	100	0.0681
0.85	82.6	100	0.0302
0.86	82.6	99.5	0.0303
0.89	87.0	99.1	0.0169
0.91	87.0	98.6	0.0170
0.93	87.0	98.2	0.0172
0.94	87.0	97.7	0.0174
1.17	91.3	39.2	0.3772
1.18	95.7	31.8	0.4669
1.25	95.7	4.1	0.3499
1.26	95.7	1.4	0.7414
1.27	1.000	0.5	0.9900
1.28	1.000	0	1.0000

ABPI: ankle brachial pressure index.