Table 5.
Kappa values and accuracy of manual sleep staging vs CReSS sleep staging in MESA by sleep apnea severity subgroups.
| Sleep Stage Discrimination | No SDB (n = 63) | Mild SDB (n = 76) | Moderate SDB (n = 73) | Severe SDB (n = 84) | ||||
|---|---|---|---|---|---|---|---|---|
| Kappa (95% CI) | Percent Accuracy | Kappa (95% CI) | Percent Accuracy | Kappa (95% CI) | Percent Accuracy | Kappa (95% CI) | Percent Accuracy | |
| CReSS Applied to Heart Rate and Airflow Signals | ||||||||
| Wake/LS/DS/REM sleep | 0.648 (0.643–0.653) | 77.7 | 0.653 (0.648–0.657) | 78.0 | 0.650 (0.646–0.655) | 77.8 | 0.621 (0.617–0.626) | 76.9 |
| Wake/sleep | 0.729 (0.723–0.736) | 90.9 | 0.734 (0.728–0.740) | 90.7 | 0.721 (0.716–0.727) | 88.9 | 0.667 (0.661–0.673) | 87.2 |
| NREM sleep/REM sleep | 0.808 (0.801–0.815) | 94.1 | 0.807 (0.801–0.813) | 93.8 | 0.781 (0.773–0.788) | 93.3 | 0.763 (0.755–0.770) | 93.0 |
| LS/DS | 0.473 (0.461–0.486) | 84.7 | 0.442 (0.429–0.455) | 85.4 | 0.479 (0.465–0.493) | 87.3 | 0.477 (0.463–0.491) | 89.6 |
| Wake/NREM sleep/REM sleep | 0.743 (0.738–0.748) | 86.5 | 0.744 (0.740–0.749) | 86.2 | 0.720 (0.716–0.725) | 84.4 | 0.677 (0.672–0.682) | 82.5 |
| CReSS Applied to Heart Rate, Airflow, and Thoracic Respiratory Effort Signals | ||||||||
| Wake/LS/DS/REM sleep | 0.687 (0.682–0.692) | 80.1 | 0.682 (0.677–0.686) | 79.8 | 0.692 (0.687–0.696) | 80.3 | 0.662 (0.657–0.666) | 79.2 |
| Wake/sleep | 0.774 (0.768–0.780) | 92.2 | 0.767 (0.761–0.772) | 91.7 | 0.770 (0.765–0.776) | 90.7 | 0.720 (0.714–0.725) | 89.1 |
| NREM sleep/REM sleep | 0.842 (0.836–0.849) | 95.1 | 0.847 (0.841–0.852) | 95.0 | 0.816 (0.810–0.823) | 94.3 | 0.790 (0.783–0.796) | 93.6 |
| LS/DS | 0.484 (0.471–0.496) | 85.3 | 0.418 (0.405–0.432) | 85.2 | 0.472 (0.458–0.486) | 87.6 | 0.465 (0.451–0.480) | 89.7 |
| Wake/NREM sleep/REM sleep | 0.785 (0.780–0.789) | 88.6 | 0.781 (0.777–0.786) | 88.1 | 0.767 (0.763–0.771) | 86.9 | 0.722 (0.718–0.727) | 84.7 |
Discriminations of wake/LS/DS/REM sleep and wake/NREM sleep/REM sleep are based on all epochs. For the discrimination of NREM sleep/REM sleep that does not include wake, we transformed the confusion matrix by removing the wake column and row; the same transformation was undertaken for the LS/DS discrimination by removing both wake and REM sleep. CI = confidence interval, CReSS = CardioRespiratory Sleep Staging, LS = light sleep (corresponding to N1 + N2), DS = deep sleep (corresponding to N3), MESA = Multi-Ethnic Study of Atherosclerosis, NREM = non-REM, REM = rapid eye movement, SDB = sleep-disordered breathing.