Table 1.
Demographic, sleep and clinical measures of the participants. Key: ISI—Insomnia severity index; PSQI—Pittsburgh sleep quality index; CSM—Composite Scale of Morningness; DBAS—Dysfunctional beliefs about sleep; GAD-7—Generalised Anxiety Disorder; PHQ-9—Patient Health Questionnaire; DLMO—dim light melatonin onset; PSG—polysomnography; TST—total sleep time; SOL—sleep onset latency; WASO—wake after sleep onset; HBTd—habitual bedtime sleep diary. Note: one participant recorded zero minutes on the PSG recording which was not recorded in the ranges.
| Variable | Mean ± SD (Range) n = 115 |
|---|---|
| Age (years): SD | 47.1 ± 14.8 (18–80) |
| BMI (kg/m2) | 25.6 ± 5.3 (17.1–43.8) |
| Female: n (%) | 80 (70%) |
| ISI | 19.9 ± 4.2 (10–28) |
| PSQI | 13.1 ± 3.3 (5–20) |
| CSM | 35.0 ± 8.3 (14–52) |
| DBAS | 5.7 ± 1.6 (1–9) |
| GAD-7 | 7.2 ± 4.9 (0–21) |
| PHQ-9 | 10.8 ± 5.5 (2–24) |
| DLMO (hh:mm) (n = 98) | 21:12 ± 1:28 (17:28–0:32) |
| PSG: TST (min) | 344.2 ± 77.1 (156.0–518.5) |
| PSG: SOL (min) | 22.0 ± 26.4 (1.0–159.0) |
| PSG: WASO (min) | 86.0 ± 54.4 (7.0–249.5) |
| PSG: sleep efficiency (%) | 74.1 ± 14.4 (43.5–94.4) |
| Diary: TST (min) | 346.6 ± 87.2 (135.0–557.1) |
| Diary: SOL (min) | 43.0 ± 39.0 (5.6–180.0) |
| Diary: WASO (min) | 57.6 ± 50.0 (2–252.0) |
| Diary: sleep efficiency (%) | 75.7 ± 15.2 (39.1–98.2) |
| Phase angle HBTd—DLMO (min) | 96.3 ± 88.6 (−108–276) |