Table 4.
Sensitivity, specificity, PPV and NPV, and positive and negative likelihood ratios for different AHI cutoffs
| Optimal AHI* | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | Positive likelihood ratio | Negative likelihood ratio | |
|---|---|---|---|---|---|---|---|
| AHI ≥5 | |||||||
| In-laboratory PDX | 5.7 | 95 | 96 | 98 | 89 | 23.8 | 0.05 |
| At-home PDX | 7.4 | 77 | 76 | 88 | 58 | 3.2 | 0.3 |
| Separate PSG | 7.0 | 80 | 80 | 91 | 63 | 4.0 | 0.3 |
| AHI ≥15 | |||||||
| In-laboratory PDX | 14.7 | 90 | 91 | 85 | 94 | 9.8 | 0.1 |
| At-home PDX | 12.9 | 87 | 85 | 77 | 92 | 5.9 | 0.2 |
| Separate PSG | 14.2 | 90 | 91 | 85 | 94 | 9.8 | 0.1 |
| AHI ≥30 | |||||||
| In-laboratory PDX | 21.8 | 100 | 100 | 100 | 100 | ** | 0 |
| At-home PDX | 18.6 | 90 | 91 | 75 | 97 | 9.8 | 0.1 |
| Separate PSG | 20.5 | 95 | 94 | 83 | 98 | 15.4 | 0.1 |
Notes:
*
AHI of test measure (left column) at which there is an optimal balance between sensitivity and specificity.
**
Undefined due to division by zero.
Abbreviations: PSG, polysomnography; AHI, apnea hypopnea index; PPV, positive predictive value; NPV, negative predictive value.