Table 2 Comparison of predictive validity
Evaluation method | Total (n = 47) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | |
|---|---|---|---|---|---|---|
correct position (n = 44) | incorrect position (n = 3) | |||||
Ultrasound (+) | 38 | 1 | 86.4 | 66.7 | 97.4 | 25.0 |
(−) | 6 | 2 | ||||
Auscultation (+) | 44 | 2 | 100.0 | 33.3 | 95.7 | 100.0 |
(−) | 0 | 1 | ||||
pH (+) | 31 | 1 | 91.2 | 66.7 | 96.9 | 40 |
measuring* (−) | 3 | 2 | ||||