Table 2.
Optimal cut-off points of sigh index (in N3 sleep and in REM sleep) to distinguish participants with multiple system atrophy (MSA) from those with Parkinson’s disease (PD), isolated REM sleep behavior disorder (iRBD) and controls, evaluated using Receiver Operating Characteristics Curves
| Cutoff (sighs/h) | Specificity (%) | Sensitivity (%) | PPV | NPV | Accuracy | Threshold | Bacc | Auc | |
|---|---|---|---|---|---|---|---|---|---|
| MSA vs PD | |||||||||
| N3 | 4.32 | 32 | 93 | 0.76 | 0.67 | 0.75 | 0.56 | 0.56 | 0.65 |
| REM | 1.19 | 83 | 45 | 0.81 | 0.49 | 0.60 | 0.64 | 0.49 | 0.60 |
| N3 & REM | NA | 57 | 70 | 0.79 | 0.44 | 0.66 | 0.72 | 0.63 | 0.65 |
| MSA vs iRBD | |||||||||
| N3 | 4.35 | 32 | 96 | 0.63 | 0.85 | 0.67 | 0.391 | 0.61 | 0.66 |
| REM | 1.20 | 83 | 79 | 0.84 | 0.77 | 0.80 | 0.65 | 0.74 | 0.83 |
| N3 & REM | NA | 53 | 82 | 0.7 | 0.7 | 0.7 | 0.55 | 0.65 | 0.69 |
| MSA vs Control | |||||||||
| N3 | 3.4 | 38 | 95 | 0.67 | 0.84 | 0.71 | 0.44 | 0.62 | 0.69 |
| REM | 0.8 | 87 | 78 | 0.7 | 0.91 | 0.84 | 0.50 | 0.82 | 0.82 |
| N3 & REM | NA | 57 | 90 | 0.74 | 0.81 | 0.75 | 0.54 | 0.71 | 0.76 |
| MSA vs without MSA | |||||||||
| N3 | 4.35 | 31 | 95 | 0.87 | 0.58 | 0.84 | 0.7 | 0.56 | 0.66 |
| REM | 1.20 | 83 | 61 | 0.92 | 0.40 | 0.66 | 0.80 | 0.50 | 0.72 |
| N3 & REM | 3.4 | 63 | 91 | 0,8 | 0.82 | 0.8 | 0.51 | 0.75 | 0.77 |
Auc area under the curve, Bacc best accuracy, NPV negative predictive value, PPV positive predictive value.