Clinical outcomes, corrected for clustering, time, treatment and Medical Research Council dyspnoea score# for the COPD-GRIP (Chronic Obstructive Pulmonary Disease – Guidance, Research on Illness Perception) intervention group and the usual-care group
| Baseline | 6 weeks | 3 months | 9 months | Mean difference (95% CI) | Treatment*time interaction at 9 months p-values | |
| CCQ total¶ | 0.04 (−0.09–0.17) | 0.197 | ||||
| Intervention | 1.9±1.2 | 1.8±1.1 | 2.0±1.3 | 2.0±1.2 | ||
| Usual care | 1.6±1.1 | 1.7±1.1 | 1.8±1.1 | 1.7±1.1 | ||
| CRQ-SAS+ fatigue | −0.06 (−0.28–0.16) | 0.631 | ||||
| Intervention | 4.5±1.4 | 4.5±1.5 | 4.5±1.5 | 4.4±1.4 | ||
| Usual care | 4.7±1.4 | 4.8±1.4 | 4.7±1.3 | 4.7±1.4 | ||
| CRQ-SAS+ dyspnoea | 0.16 (−0.13–0.04) | 0.162 | ||||
| Intervention | 5.8±1.4 | 5.6±1.6 | 5.6±1.5 | 5.5±1.6 | ||
| Usual care | 5.6±1.5 | 5.6±1.5 | 5.6±1.4 | 5.7±1.5 | ||
| CRQ-SAS+ emotional | 0.03 (−0.21–0.27) | 0.463 | ||||
| Intervention | 5.0±1.2 | 5.2±1.3 | 5.2±1.3 | 5.1±1.3 | ||
| Usual care | 5.2±1.2 | 5.3±1.2 | 5.2±1.1 | 5.3±1.2 | ||
| CRQ-SAS+ mastery | 0.09 (−0.11–0.28) | 0.375 | ||||
| Intervention | 5.4±1.0 | 5.4±1.1 | 5.3±1.3 | 5.3±1.2 | ||
| Usual care | 5.4±1.3 | 5.4±1.3 | 5.4±1.2 | 5.5±1.2 | ||
| FPI+ | −0.12 (−0.33–0.08) | 0.074 | ||||
| Intervention | 1.7±0.7 | 1.6±0.7 | 1.6±0.7 | 1.5±0.7 | ||
| Usual care | 1.8±0.6 | 1.8±0.7 | 1.7±0.7 | 1.8±0.7 | ||
| B-IPQ§ (control) | −0.22 (−0.70–0.26) | 0.005 | ||||
| Intervention | 5.5(2.7 | 6.5±2.1 | 6.1±2.5 | 6.6±2.2 | ||
| Usual care | 6.4±2.3 | 6.5±2.1 | 6.9±1.7 | 6.2±2.3 | ||
| heiQ+ (HDB) | −0.12 (−0.26–0.03) | 0.024 (6 weeks) | ||||
| Intervention | 2.8±0.7 | 3.1±0.7 | 3.0±0.5 | 2.9±0.8 | ||
| Usual care | 3.1±0.7 | 3.1±0.6 | 3.1±0.6 | 3.1±0.6 |
Data are presented as mean±sd, unless otherwise stated. CCQ: Clinical COPD Questionnaire; CRQ-SAS: self-administered Chronic Respiratory Disease Questionnaire short form; FPI: Functional Performance Inventory; B-IPQ: brief illness perception questionnaire; heiQ: Health Education Impact Questionnaire; HDB: health-directed behaviour. #: lower scores mean less burden of dyspnoea; ¶: lower score means better health-related quality of life (HRQoL); +: higher scores mean better HRQoL, functional performance and health education impact; §: lower scores on consequences, identity, concern and emotional response and higher scores on timeline, personal control, treatment control and comprehensibility mean more positive perceptions.