Psychometric analysis of clinical chronic obstructive pulmonary disease questionnaire and chronic obstructive pulmonary disease assessment test and its correlation with St. George respiratory questionnaire in chronic obstructive pulmonary disease patients

Introduction: Chronic obstructive pulmonary disease (COPD) is a disease of respiratory airflow obstruction. There are > 80 tools to measure various aspects of COPD patients' well-being. This study aimed to evaluate the reliability and consistency of CAT and clinical COPD questionnaire (CCQ) and their correlation with St. George respiratory questionnaire (SGRQ). Methods: A prospective observational comparative study was conducted for 6 months in the pulmonology department of a tertiary care hospital. The following questionnaires were employed to evaluate the state of health of COPD patients: modified Medical Research Council (mMRC), COPD assessment test (CAT), CCQ, and SGRQ. Consistency and inter-rater reliability of CAT and CCQ scales was performed by taking into account the scores of four assessors. Results: Of the 52 patients included, 96% were male, and 4% were female. Cronbach's alpha was 0.620 (CAT score) and 0.861 (CCQ score). The percentage of patients with an mMRC scale of grade 0, 1, 2, 3, and 4 was 4%, 23%, 38%, 8%, and 27%, respectively. SGRQ showed a moderate correlation with CCQ (0.621) and CAT (0.652) scores. Conclusion: The psychometric properties of CAT and CCQ were consistent and satisfactory. Reliability and internal consistency of CAT and CCQ were good and can be employed easily for examining the health state of COPD patients.