Table 3.
Differences of the Subjective Sleep Measurements in the SR-Sleep-Device/Placebo-Device Groups
| (M ± SD) | SR-Sleep-Device Group (N = 20) | Placebo-Device Group (N=20) | p2 | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Pre (1) | After 2 Weeks (2) | After 4 Weeks (3) | p1 | Pre (1) | After 2 Weeks (2) | After 4 Weeks (3) | p1 | ||
| Sleep diary | |||||||||
| SOL | 50.74 ± 22.48 | 41.41 ± 17.79 | 36.06 ± 15.48 | 0.004** (1 > 3) | 52.12 ± 43.52 | 38.16 ± 30.02 | 40.15 ± 39.02 | 0.638 | 0.175 |
| TIB | 511.77 ± 84.44 | 503.38 ± 103.51 | 503.04 ± 50.51 | 0.756 | 494.03 ± 66.08 | 515.91 ± 70.94 | 505.50 ± 82.46 | 0.064 | 0.204 |
| TST | 380.79 ± 84.92 | 389.42 ± 113.39 | 402.44 ± 67.99 | 0.047* (3 > 1) | 368.49 ± 86.95 | 410.53 ± 51.49 | 396.07 ± 68.84 | 0.074 | 0.923 |
| SE | 0.74 ± 0.11 | 0.77 ± 0.12 | 0.8 ± 0.1 | 0.017* (3 > 1) | 0.74 ± 0.14 | 0.8 ± 0.1 | 0.79 ± 0.11 | 0.259 | 0.184 |
| WASO | 29.42 ± 36.73 | 24.38 ± 38.26 | 28.48 ± 39.52 | 0.646 | 18.97 ± 21.17 | 23.4 ± 21.63 | 19.46 ± 24.34 | 0.471 | 0.945 |
| PSQI | |||||||||
| Subjective sleep quality | 1.95 ± 0.51 | 1.5 ± 0.51 | 1.3 ± 0.57 | 0.001** (1 > 2, 3) | 2.1 ± 0.64 | 1.75 ± 0.64 | 1.85 ± 0.67 | 0.042* (1 > 2) | 0.046* |
| Sleep latency | 2.1 ± 0.79 | 1.9 ± 0.72 | 1.6 ± 0.75 | 0.003** (1, 2 > 3) | 2.2 ± 0.95 | 2 ± 0.86 | 2.05 ± 0.83 | 0.485 | 0.142 |
| Sleep duration | 1.7 ± 0.73 | 1.4 ± 0.88 | 1.45 ± 0.89 | 0.021* (1 > 2) | 2.05 ± 0.89 | 1.7 ± 0.86 | 1.55 ± 1.00 | 0.009** (1 > 2, 3) | 0.398 |
| Habitual sleep efficiency | 1.65 ± 0.88 | 1.75 ± 0.79 | 1.55 ± 0.76 | 0.646 | 2.45 ± 0.89 | 1.9 ± 0.97 | 1.95 ± 1.1 | 0.070 | 0.301 |
| Sleep disturbance | 1.6 ± 0.68 | 1.4 ± 0.6 | 1.5 ± 0.69 | 0.336 | 1.8 ± 0.52 | 1.7 ± 0.47 | 1.55 ± 0.51 | 0.093 | 0.583 |
| Use of sleep medicine | 1.7 ± 1.45 | 1.6 ± 1.5 | 1.4 ± 1.57 | 0.223 | 2.1 ± 1.41 | 2.1 ± 1.41 | 2.15 ± 1.35 | 0.368 | 0.445 |
| Daytime dysfunction | 1.3 ± 0.86 | 1.05 ± 0.6 | 1.15 ± 0.67 | 0.301 | 1.3 ± 0.86 | 0.95 ± 0.76 | 1.05 ± 0.76 | 0.186 | 0.547 |
| Global score | 12 ± 2.43 | 10.6 ± 2.23 | 9.95 ± 2.06 | 0.034* (1 >2, 3) | 14 ± 3.03 | 12.1 ± 3.84 | 12.15 ± 4.06 | 0.044* (1 > 2, 3) | 0.445 |
| ESS | 8.6 ± 4.26 | 7.55 ± 3.89 | 7.15 ± 3.59 | 0.019* (1 > 3; p = 0.055) | 6.55 ± 5.09 | 6.4 ± 5.12 | 6.2 ± 4.84 | 0.430 | 0.289 |
Notes: *p < 0.05, **p < 0.01. (1): pre, (2): after 2 weeks, (3): after 4 weeks.
Abbreviations: p1, Friedman test; post hoc, Wilcoxon test; p2, Mann–Whitney U-test (comparison of the difference between the two groups before and after 4 weeks); SOL, sleep onset latency; TIB, time in bed; TST, total sleep time; SE, sleep efficiency; WASO, wake after sleep onset; PSQI, Pittsburgh Sleep Quality Inventory; ESS, Epworth Sleepiness Scale.