Table 2.
Comparison of diagnostic performance of observer A and B.
| Level of Observation | Observer | n | TP | TN | FP | FN | Sen. % | Spe. % | PPV % | NPV % | Acc. % |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Patient | Observer A | 109 | 2 | 31 | 76 | 0 | 100.0% | 29.0 | 2.6 | 100.0 | 30.3 |
| Observer B | 2 | 31 | 76 | 0 | 100.0% | 29.0 | 2.6 | 100.0 | 30.3 | ||
| Difference Δ | 0 | 0 | 0 | 0 | 0.0% | 0.0 | 0.0 | 0.00 | 0.0 | ||
| Vessel | Observer A | 436 | 0 | 306 | 128 | 2 | 0.0% | 70.5 | 0.0 | 99.4 | 70.2 |
| Observer B | 1 | 314 | 120 | 1 | 50.0% | 72.4 | 0.8 | 99.7 | 72.3 | ||
| Difference Δ | 1 | 8 | −8 | −1 | 50.0% | +1.8 | +0.8 | +0.3 | +2.1 | ||
| Segment | Observer A | 1456 | 0 | 1265 | 189 | 2 | 0.0% | 87.0 | 0.0 | 99.8 | 86.9 |
| Observer B | 0 | 1271 | 183 | 2 | 0.0% | 87.4 | 0.0 | 99.8 | 87.3 | ||
| Difference Δ | 0 | 6 | −6 | 0 | 0.0% | +0.4 | 0.0 | 0.0 | +0.4 |
ICA was used as the standard of reference. Thresholds for coronary artery disease were ICA ≥ 50% diameter and CT-FFR ≤ 0.80. Acc. = accuracy; CT-FFR = CT-derived fractional flow reserve; FN = false negative; FP = false positive; ICA = invasive coronary angiography; NPV = negative predictive value; PPV = positive predictive value; Sen. = sensitivity; Spe. = specificity; TN = true negative; TP= true positive.