Adaptation and validation of the Chinese version of Dyspnoea-12 scale in individuals with chronic obstructive pulmonary disease.

INTRODUCTION Dyspnoea-12 scale is a validated assessment tool, capturing the perception of dyspnoea and its physical and affective effects in individuals with chronic obstructive pulmonary disease (COPD). A validated version for the Chinese-speaking population has been unavailable. OBJECTIVE To develop a Chinese version of D-12 (D-12-C) scale and evaluate its validity and reliability. METHODS D-12 was translated from English to traditional Chinese in collaboration with a physician and a linguist. Back translation was adopted to ensure accuracy of the translation. A total of 155 COPD patients were recruited to test the reliability and validity of the D-12-C scale. Internal reliability and test-retest reliability were measured with Cronbach's alpha coefficient and intra-class correlation coefficient, respectively. Construct validity was assessed through exploratory factor analysis (EFA). Concurrent validity was assessed by the correlation of D-12-C total score and sub-scores and the Chinese version of Saint George's Respiratory Questionnaire (SGRQ), 36-Item Short Form Health Survey (SF-36), COPD Assessment Test (CAT) and Hospital Anxiety and Depression Scale (HADS) total score and sub-scores. RESULTS The two-factor structure of D-12-C was confirmed by EFA. D-12-C and its sub-scores demonstrated high level of internal reliability (Cronbach's alpha = 0.88) and moderate level of test-retest reliability. D-12-C total score, physical and affective sub-scores were significantly correlated to SGRQ total score (rs  = 0.59, p < 0.001) and activity sub-score (rs  = 0.38, p = 0.006), SF-36 mental health sub-score (rs  = -0.36, p < 0.001), CAT (rs  = 0.56, p < 0.001), HADS anxiety (rs  = 0.51, p < 0.001) and depression sub-scores (rs  = 0.44, p < 0.001). CONCLUSION D-12-C scale was developed, which demonstrated satisfactory reliability and validity in measuring dyspnoea among COPD patients.