Table 5.
Mediation models.
| Model | Treatment Component | (Action Theory) | (Conceptual Theory) | Total Effect (a × b + c) | (Mediation) |
|---|---|---|---|---|---|
| Path a | Path b | Indirect Effect | |||
| Outcome-> | COPD Self-Efficacy | Insomnia Severity | Insomnia Severity | ||
| 1. COPD Self-Efficacy and Insomnia Severity | COPD-ED | −6.2 (4.4) | 0.08 (0.03)* | −1.8 (1.3) | −0.49 (0.39) |
| CBT-I | −2.7 (4.2) | −4.7 (1.2)* | −0.22 (0.35) | ||
| COPD-ED × CBT-I | 5.9 (6.1) | 2.6 (1.7) | 0.47 (0.52) | ||
| Outcome-> | Sleep Self-Efficacy | Insomnia Severity | Insomnia Severity | ||
| 2. Sleep Self-Efficacy and Insomnia Severity | COPD-ED | 0.97 (1.8) | −0.47 (0.06)* | −1.5 (1.3) | −0.46 (0.84) |
| CBT-I | 2.2 (1.7) | −4.5 (1.2)* | −1.0 (0.82) | ||
| COPD-ED × CBT-I | −0.31 (2.4) | 2.1 (1.8) | 0.14 (1.1) | ||
| Outcome-> | Beliefs and Attitudes about Sleep | Insomnia Severity | Insomnia Severity | ||
| 3. Beliefs and Attitudes about Sleep and Insomnia Severity | COPD-ED | −0.75 (0.35)* | 1.2 (0.35)* | −2.0 (1.3) | −0.90 (0.49) |
| CBT-I | −0.88 (0.33)* | −4.8 (1.2)* | −1.05 (0.50)* | ||
| COPD-ED × CBT-I | 0.64 (0.48) | 2.7 (1.8) | 0.77 (0.62) | ||
| Outcome-> | CRQ Emotional Function | Insomnia Severity | Insomnia Severity | ||
| 4. CRQ Emotional Function and Insomnia Severity | COPD-ED | 0.37 (0.21) | −1.9 (0.57)* | −1.8 (1.3) | −0.72 (0.46) |
| CBT-I | 0.45 (0.21)* | −5.0 (1.2)* | −0.87 (0.47) | ||
| COPD-ED × CBT-I | −0.56 (0.29) | 2.5 (1.8) | 1.1 (0.65) | ||
| Outcome-> | COPD Self-Efficacy | Fatigue | Fatigue | ||
| 5. COPD Self-Efficacy and CRQ Fatigue | COPD-ED | −6.2 (4.4) | −0.01 (0.001)* | 0.16 (0.23) | 0.07 (0.06) |
| CBT-I | −2.7 (4.2) | 0.44 (0.22)* | 0.03 (0.05) | ||
| COPD-ED × CBT-I | 5.9 (6.1) | −0.43 (0.31) | −0.07 (0.08) | ||
| Outcome-> | Sleep Self-Efficacy | Fatigue | Fatigue | ||
| 6. Sleep Self-Efficacy and CRQ Fatigue | COPD-ED | 0.97 (1.8) | 0.03 (0.01)* | 0.18 (0.23) | 0.03 (0.05) |
| CBT-I | 2.2 (1.7) | 0.46 (0.22)* | 0.07 (0.06) | ||
| COPD-ED × CBT-I | −0.31 (2.4) | −0.42 (0.31) | −0.01 (0.07) | ||
| Outcome-> | Beliefs and Attitudes about Sleep | Fatigue | Fatigue | ||
| 7. Belief and Attitudes about Sleep and CRQ Fatigue | COPD-ED | −0.75 (0.35)* | −0.09 (0.06) | 0.29 (0.22) | 0.07 (0.06) |
| CBT-I | −0.88 (0.33)* | 0.51 (0.21)* | 0.08 (0.06) | ||
| COPD-ED × CBT-I | 0.64 (0.48) | −0.58 (0.31) | −0.06 (0.06) | ||
| Outcome-> | CRQ Emotional Function | Fatigue | Fatigue | ||
| 8. CRQ Emotional Function and CRQ Fatigue | COPD-ED | 0.37 (0.21) | 0.44 (0.10)* | 0.18 (0.23) | 0.16 (0.10) |
| CBT-I | 0.45 (0.21)* | 0.49 (0.22)* | 0.20 (0.10) | ||
| COPD-ED × CBT-I | −0.56 (0.29) | −0.46 (0.31) | −0.25 (0.14) |
All models are adjusted for baseline measures of the mediator and outcome. Cell values are parameter estimate (standard error). *P < .05. Italic: P < .10. -> = effects on variables in columns to the right, CBT-I = cognitive behavioral therapy for insomnia, COPD-ED = chronic obstructive pulmonary disease education, CRQ = Chronic Respiratory Disease Questionnaire.