Development of the Japanese version of the COPD Assessment Test

BackgroundWe aimed to develop the Japanese version of the COPD Assessment Test^TM (CAT), which was recently developed in overseas countries, to measure the health status of patients with chronic obstructive pulmonary disease (COPD) and to validate its psychometric properties.MethodsThe original CAT was translated to Japanese through linguistic validation. Then, an Internet-based survey was conducted by including 301 Japanese patients with COPD who were over 40 years of age and had a history of smoking, to assess the reliability and validity of the translated CAT.ResultsThe Japanese CAT was shown to have high internal consistency (Cronbach's α coefficient: 0.891). The assessment using the Japanese CAT was highly correlated with assessment using the COPD-specific St. George's Respiratory Questionnaire (r=0.820). The assessment also showed correlation between the Japanese CAT and a generic health-related quality of life (QOL) questionnaire (SF-12v2).ConclusionThe Japanese version of the CAT has high reliability and validity, and can be expected to serve as a short and simple questionnaire for precise assessment of the health status of Japanese patients with COPD.