Table 4 Relevant indicators of PHQ-9 validity analysis
Cut-off value | Sensitivity | Specificity | Positive predictive value | Negative predictive value | Youden index |
|---|---|---|---|---|---|
3 | 95.6% | 55.5% | 41.1% | 97.5% | 0.511 |
4 | 94.1% | 68.4% | 49.2% | 97.3% | 0.625 |
5 | 91.2% | 76.6% | 55.9% | 96.4% | 0.678 |
6 | 82.4% | 80.4% | 57.7% | 93.3% | 0.628 |
7 | 77.9% | 85.2% | 63.1% | 92.2% | 0.631 |
8 | 69.1% | 87.1% | 63.5% | 89.7% | 0.562 |
9 | 61.8% | 90.9% | 68.9% | 88.0% | 0.527 |
10 | 54.4% | 93.8% | 74.0% | 86.3% | 0.482 |