Table 4.
Descriptive Statistics for Continuous Variables Among the Three Classes
| 1. Partial-Responders | 2. Initial-Responders | 3. Optimal-Responders | Overall F (df) | Cohen’s d | |||
|---|---|---|---|---|---|---|---|
| n = 97 | n = 25 | n = 18 | 1 vs 2 | 1 vs 3 | 2 vs 3 | ||
| Age | 46.54 (12.57) | 46.84 (12.82) | 49.17 (12.43) | 0.33 (2, 137) | −0.02 | −0.21 | −0.18 |
| Age: 1st insomnia episode | 31.76 (15.60) | 31.60 (16.22) | 32.27 (12.40) | 0.01 (2, 130) | 0.01 | −0.03 | −0.04 |
| Age: 1st depression episode | 25.92 (14.89) | 26.64 (16.03) | 28.24 (11.75) | 0.18 (2, 135) | −0.05 | −0.16 | −0.11 |
| Chronotype | 31.09 (8.12) | 31.08 (8.02) | 32.12 (6.11) | 0.12 (2, 129) | 0.00 | −0.13 | −0.14 |
| FIRST | 25.02 (6.08) | 26.15 (5.98) | 22.83 (5.34) | 1.60 (2, 117) | −0.19 | 0.37 | 0.58 |
| Number of sessions attended | 5.32 (2.30) | 6.29 (1.33) | 6.24 (1.68) | 2.17 (3, 123)† | −0.46 | −0.41 | 0.04 |
|
| |||||||
| GSES | |||||||
|
| |||||||
| BL | 8.27 (3.03) | 8.67 (3.64) | 7.44 (2.94) | 0.80 (2, 127) | −0.12 | 0.27 | 0.36 |
| MID | 6.48 (3.32) | 5.72 (3.89) | 4.06 (2.24) | 3.78 (2, 89)* | 0.22 | 0.78* | 0.53 |
| POST | 5.52 (3.30) | 3.91 (2.89) | 2.47 (1.33) | 7.85 (2, 97)*** | 0.50† | 1.02*** | 0.61 |
|
| |||||||
| DBAS | |||||||
|
| |||||||
| BL | 6.08 (1.38) | 6.68 (1.69) | 5.68 (1.70) | 2.55 (2, 127)† | −0.42 | 0.28 | 0.59† |
| MID | 5.24 (1.89) | 5.16 (1.90) | 3.79 (1.52) | 4.42 (2, 88)* | 0.04 | 0.80* | 0.80† |
| POST | 4.49 (1.79) | 3.83 (2.01) | 3.12 (1.64) | 3.94 (2, 95)* | 0.36 | 0.78* | 0.38 |
|
| |||||||
| ISI | |||||||
|
| |||||||
| BL | 19.07 (4.01) | 19.44 (3.76) | 18.00 (4.91) | 0.70 (2, 137) | −0.09 | 0.26 | 0.34 |
| ISI slope a | −1.86 (0.96) | −2.13 (1.05) | −2.55 (1.10) | 3.97 (2, 137)* | 0.28 | 0.70* | 0.39 |
| MID | 13.05 (5.39) | 9.94 (5.45) | 8.11 (5.09) | 6.74 (2, 89)** | 0.58† | 0.93** | 0.35 |
| POST | 10.47 (5.67) | 5.30 (5.79) | 4.71 (3.89) | 11.94 (2, 97)*** | 0.91*** | 1.08*** | 0.12 |
| FU | 12.16 (6.51) | 8.54 (7.61) | 4.25 (5.46) | 6.55 (2, 54)** | 0.53 | 1.26** | 0.64 |
|
| |||||||
| HRSD | |||||||
|
| |||||||
| BL | 17.55 (3.58) | 17.60 (2.55) | 16.22 (3.15) | 1.23 (2, 137) | −0.02 | 0.38 | 0.49 |
| MID, % Responders | 12.24 (5.12), 27.8% | 8.71 (6.84), 58.8% | 2.41 (2.00), 100% | 24.48 (2, 85)*** | 0.64* | 2.14*** | 1.25** |
| POST, % Responders | 11.41 (5.33), 30.5% | 1.50 (1.30), 100% | 2.75 (2.67), 87.5% | 53.70 (2, 94)*** | 2.14*** | 1.76*** | −0.63 |
| FU, % Responders | 9.66 (5.85), 53.1% | 7.38 (6.49), 69.2% | 1.33 (1.15), 100% | 10.32 (2, 54)*** | 0.38 | 1.64*** | 1.27* |
Note. Mean (standard deviation) are shown for descriptive statistics. FIRST = Ford’s Insomnia Response to Stress Test, GSES = Glasgow Sleep Effort Scale, DBAS = Dysfunctional Beliefs and Attitude about Sleep Scale, ISI = Insomnia Severity Index, HRSD = Hamilton Rating Scale of Depression (less sleep-related items); % of responders (defined as 50% or more reduction in HRSD scores) are also listed. BL = baseline, MID = mid-treatment, POST = immediately post-treatment, FU = 2-year follow-up.
“ISI slope” (i.e., initial treatment response) is the slope of ISI during the first six weeks of the treatment as identified by Manber et al. (2016). Cohen’s d-values above 0.2, 0.5 and 0.8 suggesting small, moderate and large effect sizes, respectively. Statistical significance was based on Tukey’s honest significant difference test for post hoc pairwise tests adjusting for multiple comparisons.
p < .1,
p < .05,
p < .01,
p < .001.