The Development and Validation of a New Questionnaire to Address the Gap between the Actual and Desired States in COPD Patients

Abstract

Background: Numerous quality of life (QOL) assessment tools are available for patients with chronic obstructive pulmonary disease (COPD); however, most only focus on the patient’s actual state, and very few assess the patient’s desired state. Objective: To develop a questionnaire that can assess COPD patients’ desired states and to verify the usefulness of the findings. Methods: We interviewed COPD patients to identify components that best reflected the patients’ desired movement/activities. Two types of questionnaires were created with each component intended for self-assessment by actual and desired states. The revised questionnaire included the appropriate components based on the results of the preliminary survey. A multicenter study was performed using the final questionnaire. Results: We selected 32 components of the patients’ desired movement/activity from interviews with 22 COPD patients. The final questionnaire consisted of eight components and had a sufficiently high internal consistency (Cronbach’s α > 0.8). Three hundred and sixty two COPD patients participated in the validation study. The gap score (the difference between actual and desired scores) was significantly correlated with the predicted percentage of the forced expiratory volume in 1 s, dyspnea scale, and the COPD assessment test (CAT) (p < 0.0001). Oxygen therapy and frequent exacerbations exhibited unfavorable gap scores (p < 0.001). Multiple regression analysis on actual scores identified dyspnea scale, CAT, oxygen use, unemployment, exacerbation and heart failure to be independent explanatory variables (adjusted R2=0.63). Whereas only dyspnea scale and CAT were significant predictors in gap score (adjusted R2=0.32). Conclusion: The gap and actual scores evaluate the different aspect of the patients’ state. Evaluating the gap scores in patients might be useful in the assessment of the suitability of ongoing medical interventions and in the determination of future therapeutic goals.