Table 4.
Confusion matrix for epoch-by-epoch sleep staging in SHHS.
| CReSS Sleep Staging | PSG Sleep Staging | |||
|---|---|---|---|---|
| CReSS Applied to Heart Rate and Airflow Signals | ||||
| Wake | REM Sleep | Light Sleep | Deep Sleep | |
| Wake | 39,954 | 942 | 6,768 | 324 |
| 61.1%* | 2.1% | 4.8% | 0.9% | |
| REM sleep | 4,009 | 33,326 | 4,934 | 251 |
| 6.1% | 73.4%* | 3.5% | 0.7% | |
| Light sleep | 20,919 | 11,001 | 121,248 | 18,100 |
| 32.0% | 24.2% | 85.5%* | 52.4% | |
| Deep sleep | 511 | 161 | 8,783 | 15,888 |
| 0.8% | 0.4% | 6.2% | 46.0%* | |
| PPV | 83.3% | 78.4% | 70.8% | 62.7%* |
| CReSS Applied to Heart Rate, Airflow, and Thoracic Respiratory Effort Signals | ||||
| Wake | REM Sleep | Light Sleep | Deep Sleep | |
| Wake | 44,270 | 562 | 5,566 | 197 |
| 67.7%* | 1.2% | 3.9% | 0.6% | |
| REM sleep | 2,917 | 36,584 | 4,888 | 208 |
| 4.5% | 80.5%* | 3.4% | 0.6% | |
| Light sleep | 18,001 | 8,192 | 123,168 | 17,859 |
| 27.5% | 18.0% | 86.9%* | 51.7% | |
| Deep sleep | 205 | 92 | 8,111 | 16,299 |
| 0.3% | 0.2% | 5.7% | 47.2%* | |
| PPV | 87.5% | 82.0% | 73.7% | 66.0%* |
*Values are the number of epochs of each PSG-scored sleep stage that were correctly identified by CReSS and the percentage of epochs within each PSG-defined sleep stage that were correctly identified by CReSS (that is, sensitivity). The percentage values labeled as PPV represent the percentage of epochs within each CReSS-defined sleep stage that was correct per PSG. CReSS = CardioRespiratory Sleep Staging, PPV = positive predictive value, PSG = polysomnography, REM = rapid eye movement, SHHS = Sleep Heart Health Study.