Table 2.

VSW's performance in 4-class sleep stage detection against the PSG reference.

Sleep stage	Kappa (95% CI)	Accuracy (95% CI)	PPV (95% CI)	Sensitivity (95% CI)
Overall	0.64 (0.18, 0.82)	0.78 (0.58, 0.89)	NA	NA
Wake	0.70 (0.43, 0.90)	0.92 (0.76, 0.98)	0.82 (0.51, 0.98)	0.71 (0.45, 0.94)
Light	0.60 (0.29, 0.78)	0.80 (0.66, 0.89)	0.80 (0.55, 0.91)	0.81 (0.59, 0.94)
Deep	0.66 (0.17, 0.91)	0.92 (0.84, 0.98)	0.69 (0.09, 0.97)	0.77 (0.37, 0.98)
REM	0.74 (0.38, 0.90)	0.92 (0.82, 0.98)	0.76 (0.44, 0.96)	0.84 (0.47, 0.99)

CI, confidence interval; PPV, Positive Predictive Value; REM, Rapid Eye Movement.