Table 4.
Adjusted Means and Changes Scores on PSG-Defined Sleep Variables According to Group and Time (pre and post only)
| Means (standard errors), by time and change scores | Comparison between groups |
|||||
|---|---|---|---|---|---|---|
| Time (or change) | CBT | CT | BT | Effect | F(2,180)a | Post-hoca |
| Sleep Onset Latency (in min) | ||||||
| t1 (Pre) | 13.27 (1.93) | 17.74 (2.20) | 17.24 (1.55) | cond/t1 | 1.98, p = .14 | |
| t2 (Post) | 9.45 (1.36) | 17.85 (2.50) | 12.36 (1.34) | cond/t2 | 6.04, p = .00 (.00) | CBT=BT<CT |
| Change t1-t2 (ES) | −3.82*(−0.29) | 0.12 NS (0.01) | −4.88***(−0.37) | cond/t1-t2 | 2.10, p = .13 | |
| Wake After Sleep Onset (in min) | ||||||
| t1 (Pre) | 47.15 (4.15) | 46.65 (3.92) | 54.73 (4.35) | cond/t1 | 1.44, p = .24 | |
| t2 (Post) | 43.19 (3.97) | 48.73 (4.61) | 41.22 (3.99) | cond/t2 | 0.93, p = .39 | |
| Change t1-t2 (ES) | −3.96 NS (−0.13) | 2.08 NS (0.07) | −13.51***(−0.46) | cond/t1-t2 | 4.41, p =.01 (.01) | BT>CT |
| Total Sleep Time (in min) | ||||||
| t1 (Pre) | 387.61 (5.14) | 388.60 (5.31) | 381.97 (5.59) | cond/t1 | 0.49, p = .61 | |
| t2 (Post) | 389.88 (5.76) | 380.72 (6.28) | 388.81 (4.66) | cond/t2 | 0.80, p = .45 | |
| Change t1-t2 (ES) | 2.27 NS (0.06) | −7.88 NS (−0.20) | 6.84 NS (0.17) | cond/t1-t2 | 1.94, p = .15 | |
| Total Time in Bed (in min) | ||||||
| t1 (Pre) | 457.57 (2.85) | 459.14 (2.39) | 461.54 (2.81) | cond/t1 | 0.55, p = .58 | |
| t2 (Post) | 448.41 (2.74) | 454.83 (3.70) | 450.40 (2.39) | cond/t2 | 0.96, p = .38 | |
| Change t1-t2 (ES) | −9.16**(−0.43) | −4.31 NS (−0.20) | −11.14**(−0.52) | cond/t1-t2 | 0.78, p = .46 | |
| Sleep Efficiency (%) | ||||||
| t1 (Pre) | 84.27 (1.06) | 84.56 (1.06) | 82.71 (1.15) | cond/t1 | 0.93, p = .40 | |
| t2 (Post) | 87.08 (1.02) | 83.85 (1.17) | 86.43 (0.99) | cond/t2 | 2.87, p = .06 | |
| Change t1-t2 (ES) | 2.81*(0.37) | −0.71 NS (−0.09) | 3.71***(0.49) | cond/t1-t2 | 6.36, p = .00 (.00) | CBT=BT>CT |
*
p < .05
**
p < .01
***
p < .001
Note. All means (standard errors) and change scores are adjusted for site and stratification effects.
a
p-values in parentheses are corrected for multiplicity. ES = effect size (Cohen’s d) for change scores.