Table 4: Diagnostic polysomnographic characteristics of participants categorized based on occurrence of supine sleep.
| Variable | Supine Sleep Absent N = 13 (5%) | Supine Sleep Present N = 230 (95%) | p value |
| Study Protocol [n (%)] | |||
| Full-night | 12 (92) | 174 (76) | 0.298 |
| Split-night | 1 (8) | 56 (24) | |
| Total time in bed (minutes) | 464.6 ± 41.4 | 460.0 ± 52.6 | 0.688 |
| Total sleep time (minutes) | 307.1 ± 95.3 | 343.7 ± 78.3 | 0.106 |
| Total time awake (minutes) | 157.8 ± 75.7 | 116.3 ± 84.3 | 0.136 |
| Sleep efficiency (%) | 65.3 ± 18.4 | 74.3 ± 16.5 | 0.062 |
| Sleep position (%) | |||
| Supine | 0 | 43.4 ± 4 | < 0.001* |
| Lateral | 91.0 ± 17.0 | 54.1 ± 27.1 | < 0.001 |
| Prone | 8.8 ± 17.0 | 2.1 ± 8.1 | 0.182 |
| Sleep latency (minutes) | 26.0 ± 25.8 | 19.2 ± 23.8 | 0.32 |
| REM1 latency (minutes) | 177.8 ± 115.4 | 156.9 ± 94.6 | 0.445 |
| Wake after sleep onset time (minutes) | 126.6 ± 66.3 | 97.6 ± 72.1 | 0.179 |
| Sleep Architecture (%) | |||
| Stage N1 | 16.4 ± 13.6 | 14.9 ± 12.2 | 0.673 |
| Stage N2 | 56.1 ± 13.7 | 54.3 ± 13.0 | 0.613 |
| Stage N3 | 16.8 ± 16.8 | 14.8 ± 11.4 | 0.55 |
| Stage REM1 | 14.7 ± 7.9 | 15.9 ± 8.7 | 0.628 |
| AHI2 (events/hour) | 11.9 ± 19.4 | 17.3 ± 21.7 | 0.376 |
| RERA3 index (events/hour) | 21.4 ± 20.9 | 22.4 ± 49.7 | 0.881 |
| MinSpO24 (%) | 83.8 ± 7.3 | 83.6 ± 7.5 | 0.943 |
*Statistically significant based on t-test; 1Rapid eye movement; 2Apnea-hypopnea index; 3Respiratory effort-related arousal index; 4Minimum oxygen saturation by pulse oximetry.