Table 2.
Baseline sleep indices and rating scales scores of participants (N = 548)
| Variable | Favorable (N = 300) Mean ± SD, N (%) |
Unfavorable (N = 248) Mean ± SD, N (%) |
P-value |
|---|---|---|---|
| Sleep indices | |||
| Desired total sleep time, h | 7.3 ± 1.5 | 7.2 ± 1.2 | 0.588 |
| Desired bedtime | 10:43 ± 1:01 PM | 10:31 ± 1:10 PM | 0.022 |
| Desired wake-up time | 6:56 ± 1:04 AM | 6:43 ± 1:01 AM | 0.022 |
| Desired time in bed, h | 8.2 ± 1.1 | 8.2 ± 1.4 | 0.876 |
| Discrepancy between desired time in bed and desired total sleep time (DBST index) | 0.9 ± 1.7 | 1.0 ± 1.7 | 0.607 |
| Bedtime | 11:06 ± 1:09 PM | 11:02 ± 1:15 PM | 0.525 |
| Sleep onset time | 12:16 ± 1:28 AM | 12:10 ± 1:30 AM | 0.419 |
| Final wake time | 6:19 ± 1:49 AM | 5:59 ± 1:45 AM | 0.033 |
| Get out of bed time | 6:59 ± 1:39 AM | 6:45 ± 1:27 AM | 0.085 |
| Sleep onset latency, h | 1.2 ± 1.2 | 1.1 ± 1.6 | 0.521 |
| Time in bed, h | 7.9 ± 1.7 | 7.7 ± 1.5 | 0.153 |
| Time in bed during 24 h, h | 7.9 ± 2.8 | 7.3 ± 3.0 | 0.014 |
| Rating scale scores | |||
| Insomnia Severity Index | 16.3 ± 5.0 | 15.4 ± 4.8 | 0.028 |
| Patient Health Questionnaire-9 | 9.7 ± 5.8 | 9.0 ± 5.6 | 0.128 |
| Dysfunctional Beliefs and Attitudes about Sleep-6 | 5.5 ± 1.7 | 5.3 ± 1.6 | 0.112 |
| Sleep-Related Safety Behaviors-10 | 20.4 ± 7.3 | 20.2 ± 7.0 | 0.725 |
| Depressive Symptoms Inventory-Suicidality Scale | 2.0 ± 2.3 | 1.5 ± 2.3 | 0.009 |