Table 11. Results of the ROC curve analysis using plasma NFL concentrations as a discriminative index.

ROC curve analysis	Cut-off value of the plasma NFL concentration (pg/ml)	Sensitivity (95% CI)	Specificity (95% CI)	AUC (95% CI)
Group
NC vs. PD/PDD	12.71	0.712 (0.569–0.829)	0.903 (0.743–0.980)	0.838 (0.754–0.921)
NC vs. AD	12.04	0.838 (0.663–0.946)	0.871 (0.702–0.964)	0.919 (0.855–0.984)
NC vs. Patient*	12.71	0.735 (0.627–0.826)	0.903 (0.743–0.980)	0.868 (0.803–0.933)
PD/PDD vs. AD	18.02	0.613 (0.422–0.782)	0.654 (0.509–0.780)	0.630 (0.507–0.753)

ROC: receiver operating characteristic AUC: area under the curve

*: including PD/PDD and AD NC: normal control PD: Parkinson’s disease

PDD: Parkinson’s disease dementia AD: Alzheimer’s disease