Figures
- FIGURE 1
Flow diagram indicating patient screening, recruitment, randomisation and follow-up. Missing sleep study data occurred in one cognitive behavioural therapy for insomnia (CBTi) study pre-treatment, and five CBTi and two control studies post-treatment (there were no significant between-group differences in rates of missing sleep study data pre- or post-treatment; both Fisher's exact p>0.05). 71 CBTi and 73 control patients had available sleep study data for mixed model analyses. ISI: insomnia severity index; OSA50: obstructive sleep apnoea 50 questionnaire; AHI: apnoea–hypopnoea index; CPAP: continuous positive airway pressure.
- FIGURE 2
Changes in apnoea–hypopnoea index (AHI) from pre- to post-treatment between groups, sleep stage and posture. Data are presented as mean±sem. CBTi: cognitive behavioural therapy for insomnia.
- FIGURE 3
Mean apnoea–hypopnoea index (AHI) and arousal index by sleep stage and sleep posture (collapsed over intervention group and time). Data are presented as mean (95% confidence interval).
Tables
- TABLE 1
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.
