Table 4.
Means and SDs for sleep hygiene variables at time 1, time 2, and difference scores.
| Sleep hygiene | Condition | DS | T1 | T2 | |
|---|---|---|---|---|---|
| Physiological*** | Sleep Smart | M (SD) | 0.50 (0.83) | 4.04 (0.75) | 4.54 (0.77) |
| Comparison | M (SD) | 0.20 (0.75) | 4.17 (0.99) | 4.37 (0.84) | |
| Cognitive | Sleep Smart | M (SD) | 0.29 (0.91) | 3.81 (0.94) | 4.12 (0.98) |
| Comparison | M (SD) | 0.18 (1.14) | 3.85 (1.13) | 4.03 (1.11) | |
| Emotional* | Sleep Smart | M (SD) | 0.43 (1.04) | 4.71 (1.05) | 5.14 (0.88) |
| Comparison | M (SD) | 0.16 (1.14) | 4.94 (1.07) | 5.11 (1.03) | |
| Sleep environment | Sleep Smart | M (SD) | 0.37(1.15) | 4.69 (1.07) | 5.06 (0.90) |
| Comparison | M (SD) | 0.20 (1.02) | 5.00 (1.13) | 5.16 (0.99) | |
| BT routine | Sleep Smart | M (SD) | 0.13 (2.20) | 3.37 (1.75) | 3.52 (1.63) |
| Comparison | M (SD) | 0.08 (1.94) | 3.63 (1.96) | 3.71 (1.84) | |
| Sleep stability | Sleep Smart | M (SD) | 0.57 (1.35) | 3.42 (1.22) | 4.00 (1.15) |
| Comparison | M (SD) | 0.45 (1.07) | 3.41 (1.17) | 3.86 (1.11) | |
| PM Caffeine use (mg/oz)* | Sleep Smart | M (SD) | −8.80 (16.05) | 13.49 (15.78) | 4.89 (8.52) |
| Comparison | M (SD) | −2.39 (10.25) | 8.09 (12.13) | 5.92 (12.20) | |
| BT screen time (min)** | Sleep Smart | M (SD) | −4.91 (26.55) | 33.41 (21.32) | 28.01 (21.06) |
| Comparison | M (SD) | 6.48 (19.18) | 20.27 (18.78) | 26.91 (20.13) |
Note: Physiological, cognitive, emotional, sleep environment, daytime sleepiness, BT routine, and sleep stability: variables from Adolescent Sleep Hygiene Scale. PM Caffeine use was based on participants' self-reported afternoon/evening caffeine use (milligrams per ounce) on sleep-wake diary. BT screen time use (eg, television, video games, computer) calculated based on participants' self-reported screen time use in hour before bed (minutes). No significant differences reported from T1 to T3 or T1 to T4 for these variables.
*
P ≤ .10.
**
P ≤ .05.
***
P ≤ .01.