Table 5.
Sleep variables measured with standard polysomnography (PSG) and with a frontal electrode set (FES) (n = 19)
| Variable | PSG | FES | p value |
|---|---|---|---|
| TRT (min) | 446.1 ± 7.0 | 442.5 ± 7.5 | 0.205a |
| TST (min) | 394.9 ± 8.7 | 391.0 ± 10.3 | 0.498a |
| SE (%) | 90.5 [84.3–93.8] | 91.3 [82.6–95.2] | 0.702b |
| WASO (min) | 32.8 [18.8–53.0] | 19.3 [13.0–46.8] | 0.070b |
| Number of awakenings | 21.7 ± 2.3 | 13.8 ± 1.5 | < 0.001a |
| Sleep latency to | |||
| N1 (min) | 9.0 [5.4–16.4] | 12.0 [6.0–22.5] | 0.056b |
| N2 (min) | 18.5 [13.5–35.1] | 19.4 [14.5–28.4] | 0.276b |
| N3 (min) | 36.7 [28.9–53.6] | 39.9 [31.0–56.7] | 0.013b |
| REM (min) | 160.0 [119.5–184.0] | 220.0 [159.5–322.0] | 0.005b |
| Time spent in sleep stages | |||
| N1 (min) | 46.6 ± 5.1 | 49.4 ± 4.6 | 0.553a |
| N2 (min) | 225.6 ± 10.1 | 244.3 ± 9.9 | 0.017a |
| N3 (min) | 73.5 [62.0–95.5] | 65.0 [39.0–85.0] | 0.094b |
| REM (min) | 40.7 ± 3.2 | 26.8 ± 4.5 | < 0.001a |
| W (min) | 42.1 [27.7–66.0] | 38.6 [18.3–59.7] | 0.587b |
| Sleep stage proportion (%) | |||
| N1 | 10.7 [7.3–13.8] | 14.4 [6.7–17.7] | 0.355b |
| N2 | 57.1 ± 2.1 | 62.7 ± 1.7 | < 0.001a |
| N3 | 18.5 [16.9–24.1] | 18.3 [11.4–21.1] | 0.142b |
| REM | 10.6 ± 0.9 | 6.8 ± 1.1 | < 0.001a |
Data presented as median [25th percentile–75th percentile] (for non-normally distributed variables) or mean ± standard deviation (for normally distributed variables)
PSG polysomnography, FES frontal electrode set, TRT total recording time, TST total sleep time, SE sleep efficiency, WASO wake after sleep onset, REM rapid eye movement sleep
a Paired samples t test
bWilcoxon signed-rank test