Health status in patients with coexistent COPD and heart failure: a validation and comparison between the Clinical COPD Questionnaire and the Minnesota

Background: Chronic obstructive pulmonary disease (COPD) and heart failure (HF) are both common diseases that coexist frequently. Patients with both diseases have worse stable state health status when compared with patients with one of these diseases. In many outpatient clinics, health status is monitored routinely in COPD patients using the Clinical COPD Questionnaire (CCQ) and in HF patients with the Minnesota Living with Heart Failure Questionnaire (MLHF-Q). This study validated and compared which questionnaire, ie, the CCQ or the MLHF-Q, is suited best for patients with coexistent COPD and HF. Methods: Patients with both COPD and HF and aged >= 40 years were included. Construct validity, internal consistency, test-retest reliability, and agreement were determined. The Short-Form 36 was used as the external criterion. All questionnaires were completed at baseline. The CCQ and MLHF-Q were repeated after 2 weeks, together with a global rating of change. Results: Fifty-eight patients were included, of whom 50 completed the study. Construct validity was acceptable. Internal consistency was adequate for CCQ and MLHF-Q total and domain scores, with a Cronbach's alpha >= 0.70. Reliability was adequate for MLHF-Q and CCQ total and domain scores, and intraclass correlation coefficients were 0.70-0.90, except for the CCQ symptom score (intraclass correlation coefficient 0.42). The standard error of measurement on the group level was smaller than the minimal clinical important difference for both questionnaires. However, the standard error of measurement on the individual level was larger than the minimal clinical important difference. Agreement was acceptable on the group level and limited on the individual level. Conclusion: CCQ and MLHF-Q were both valid and reliable questionnaires for assessment of health status in patients with coexistent COPD and HF on the group level, and hence for research. However, in clinical practice, on the individual level, the characteristics of both questionnaires were not as good. There is room for a questionnaire with good evaluative properties on the individual level, preferably tested in a setting of patients with COPD or HF, or both.