Table 2. Discriminant Analysis for the Odor Identification Tests.
| ROC AUC (95% CI) | P value | Cut-off Value | Sensitivity | Specificity | |
|---|---|---|---|---|---|
| The Sniffin' Sticks screening 12 test | |||||
| iRBD vs. HC | 0.885 (0.820–0.950) | < 0.001 | 7.5 | 83.3% | 81.5% |
| PD vs. HC | 0.941 (0.902–0.981) | < 0.001 | 7.5 | 90.7% | 81.5% |
| PD vs. iRBD | 0.699 (0.596–0.798) | < 0.001 | 4.5 | 51.9% | 87.0% |
| The brief odor identification test | |||||
| iRBD vs. HC | 0.806 (0.723–0.882) | < 0.001 | 3.5 | 55.6% | 88.9% |
| PD vs. HC | 0.940 (0.894–0.986) | < 0.001 | 3.5 | 90.7% | 88.9% |
| PD vs. iRBD | 0.744 (0.652–0.836) | < 0.001 | 3.5 | 90.7% | 44.4% |
| The validation of the brief odor identification test | |||||
| iRBD vs. HC | 0.822(0.726–0.918) | < 0.001 | 3.5 | 64.1% | 89.7% |
| PD vs. HC | 0.956 (0.914–0.998) | < 0.001 | 3.5 | 92.3% | 89.7% |
| PD vs. iRBD | 0.781 (0.680–0.882) | < 0.001 | 3.5 | 92.3% | 35.9% |
Values in bold refer to statistically significant difference (P<0.05).
Abbreviations: HC = Healthy Control; iRBD = idiopathic REM sleep behavior disorder; PD = Parkinson’s disease; ROC AUC = receiver operating characteristic area under curve.