Table III.
Accuracy of resting ankle-brachial index (ABI) in detecting any segment with total occlusion according to duplex ultrasound (DUS) imaging (whole series)
| Any segment with 100% occlusion | Sensitivity | Specificity | PPV | NPV | Accuracya | P value for accuracyb |
|---|---|---|---|---|---|---|
| All patients | 67 (61.6–71.6) | 79 (76.0–81.1) | 52 (48.7–55.6) | 87 (85.4–88.7) | 76 (73.2–77.8) | |
| Diabetics | ||||||
| Diabetics only | 58 (51.3–65.3) | 75 (71.1–79.5) | 53 (47.6–57.7) | 80 (76.6–82.2) | 70 (66.3–73.6) | <.0001 |
| Nondiabetics only | 78 (70.2–83.9) | 81 (77.6–84.0) | 52 (47.1–56.3) | 93 (91.1–94.9) | 80 (77.2–83.0) | |
| CKD | ||||||
| CKD only | 53 (39.1–65.7) | 84 (77.2–89.2) | 54 (43.7–64.6) | 83 (78.5–86.4) | 75 (69.2–81.0) | .9682 |
| Non-CKD only | 70 (64.0–74.7) | 78 (74.7–80.4) | 52 (48.2–55.5) | 88 (86.1–89.8) | 76 (73.0–78.0) |
CKD, Chronic kidney disease; NPV, negative predictive value; PPV, positive predictive value.
Values are presented as percentages (95% confidence interval).
a
Accuracy = (True positive + True negative)/(True positive + True negative + False positive + False negative).
b
χ2 test.