Polysomnographic sleep study variables pre- and post-treatment, and between-group differences pre- and during treatment
| CBTi | Control | Pre-treatment p-value | During treatment | ||||||
| Pre-treatment | Post-treatment | d | Pre-treatment | Post-treatment | d | F | p-value | ||
| AHI# events·h−1 | 36.4 (4.9) | 30.9 (5.0) | 0.2 | 37.5 (4.7) | 39.5 (4.9) | 0.1 | 0.758 | 6.4 | 0.012 |
| Arousal index# events·h−1 | 36.3 (4.2) | 32.6 (4.3) | 0.2 | 36.9 (4.2) | 36.6 (4.2) | 0.0 | 0.844 | 2.2 | 0.138 |
| ODI# events·h−1 | 27.1 (4.8) | 24.3 (4.9) | 0.1 | 30.0 (4.8) | 30.6 (4.8) | 0.0 | 0.954 | 0.1 | 0.224 |
| Respiratory event duration# s | 22.1 (1.2) | 22.5 (1.2) | 0.1 | 22.7 (1.2) | 21.9 (1.2) | 0.2 | 0.456 | 3.6 | 0.060 |
| Total number of awakenings | 37.7 (4.7) | 32.7 (4.7) | 0.2 | 35.2 (4.7) | 35.9 (4.7) | 0.0 | 0.471 | 4.9 | 0.029 |
| Total sleep time min | 375.2 (20.5) | 355.4 (21.0) | 0.2 | 358.4 (20.3) | 363.8 (20.5) | 0.1 | 0.305 | 2.4 | 0.123 |
| Sleep onset latency min | 32.5 (9.4) | 21.2 (9.7) | 0.2 | 29.2 (9.3) | 23.3 (9.4) | 0.1 | 0.626 | 0.4 | 0.550 |
| Wake after sleep onset min | 95.7 (13.6) | 69.7 (13.9) | 0.5 | 82.1 (13.4) | 77.2 (13.6) | 0.1 | 0.162 | 4.7 | 0.031 |
| Sleep efficiency % | 74.3 (2.9) | 79.3 (3.0) | 0.4 | 75.0 (2.9) | 76.1 (2.9) | 0.1 | 0.747 | 2.5 | 0.115 |
| N1 min | 84.2 (11.0) | 76.5 (11.2) | 0.1 | 82.6 (10.8) | 89.4 (11.0) | 0.1 | 0.865 | 4.7 | 0.033 |
| N2 min | 180.1 (11.0) | 164.8 (11.2) | 0.3 | 163.6 (10.8) | 164.3 (11.0) | 0.0 | 0.088 | 2.7 | 0.102 |
| N3 min | 49.1 (11.0) | 48.3 (11.2) | 0.0 | 54.3 (10.8) | 49.6 (11.0) | 0.1 | 0.409 | 0.7 | 0.421 |
| REM min | 62.3 (11.0) | 63.7 (11.2) | 0.0 | 56.2 (10.8) | 60.4 (11.0) | 0.1 | 0.237 | 0.2 | 0.639 |
| N1 % | 22.7 (3.4) | 21.9 (3.4) | 0.1 | 24.1 (3.3) | 24.5 (3.4) | 0.0 | 0.556 | 0.5 | 0.472 |
| N2 % | 48.1 (2.6) | 47.3 (2.6) | 0.1 | 45.7 (2.6) | 45.0 (2.6) | 0.1 | 0.193 | 0.0 | 0.912 |
| N3 % | 13.2 (2.2) | 13.6 (2.3) | 0.0 | 16.3 (2.3) | 15.4 (2.3) | 0.1 | 0.058 | 1.1 | 0.303 |
| REM % | 16.4 (1.6) | 17.6 (1.6) | 0.2 | 15.8 (1.6) | 16.7 (1.6) | 0.1 | 0.613 | 0.1 | 0.750 |
| Supine sleep time min | 160.3 (31.6) | 156.6 (31.9) | 0.0 | 170.3 (31.3) | 175.1 (31.3) | 0.0 | 0.658 | 0.3 | 0.571 |
| Nonsupine sleep time min | 210.6 (31.6) | 194.5 (32.0) | 0.1 | 187.4 (31.3) | 188.4 (31.4) | 0.0 | 0.306 | 0.9 | 0.345 |
| Supine sleep time % | 41.8 (8.0) | 44.0 (8.0) | 0.1 | 47.7 (7.9) | 50.8 (7.9) | 0.1 | 0.304 | 0.2 | 0.701 |
| Nonsupine sleep time % | 56.9 (8.0) | 55.6 (8.1) | 0.0 | 48.2 (7.9) | 51.7 (7.9) | 0.1 | 0.284 | 0.3 | 0.612 |
Data are presented as mean (95% confidence interval) unless otherwise stated. CBTi: cognitive behavioural therapy for insomnia; d: Cohen's d for per-group change; AHI: apnoea–hypopnoea index; ODI: oxygen desaturation index. #: collapsed over stage and posture. Bold indicates statistically significant p-values.