Figure 4
(a) Bland–Altman plot and (b) intraclass correlation coefficient was calculated between the AHI of type I PSG and the REI from portable EEG device with SpO2. (a) The Bland–Altman plots depict the mean bias (red solid line) and upper and lower limits of agreement (1.96 standard deviations from bias; black dashed lines) for each sleep parameter for the portable EEG device compared with type I PSG. The parentheses contain information about the t-test, and if the P-value is significant, it indicates that the bias, depicted to the right of the solid red line, is statistically significant. A positive solid line signifies an overestimation of the portable EEG device, while a negative line signifies an underestimation. (b) Intraclass correlation coefficient with a red solid line and 95% confidence interval.
