Proefschrift Jansen Klomp

Chapter 3
Table 2. Contingency table depicting the presence versus absence of the distal ascending aorta (defined
as grade £3) visualized with Modified TEE (index test), compared to epiaortic ultrasound (reference test).
Epiaortic Ultrasound
Grade ³3 Grade £2 Total
Modified TEE Grade ³3 159 57 216
Grade £2 9 196 205
Total 168 253 421
Sensitivity: 94.6%, specificity: 77.6%, positive predictive value: 73.7%, negative predictive value: 95.6%,
positive likelihood ratio: 4.2, negative likelihood ratio: 0.075.
MODEL PERFORMANCE
For Model 1, which included baseline characteristics, the AUC was 0.73 (95% CI:
0.68–0.78; Figure 2). When adding severity of aortic atherosclerosis visualized with
TEE, the AUC increased to 0.80 (95% CI: 0.76–0.85; Model 2). Finally, after adding
the grade of atherosclerosis of the DAA visualized with modified TEE, the AUC
significantly increased to 0.93 (95% CI: 0.90–0.96; Model 3). Calibration of the three
models is depicted in Figure 3, indicating good calibration of each model
Sensitivity
0.0 0.2 0.4 0.6 0.8 1.0
Model 3
AUC = 0.93 (95% CI: 0.90 − 0.96)
Model 2
AUC = 0.80 (95% CI: 0.76 − 0.85)
Model 1
AUC = 0.73 (95% CI: 0.68 − 0.78)
1.0 0.8 0.6 0.4 0.2 0.0
Specificity
Figure 2. Receiver operating characteristic curves for the prediction of severe atherosclerosis of the distal
ascending aorta with Model 1 (patient characteristics), Model 2 (Model 1 + conventional TEE), and Model
3 (Model 2 + modified TEE). AUC, area under the receiver operating characteristic curve
40