Validation of Chinese version of the Modified Pulmonary Functional Status and Dyspnea Questionnaire with heart failure patients in Taiwan.

BACKGROUND Dyspnea is a distressing and functionally limiting symptom that patients with heart failure commonly experience. A valid instrument to quantify dyspnea for comparison of groups and for illness management is important. OBJECTIVE To validate the Chinese version of the Modified Pulmonary Functional Status and Dyspnea Questionnaire. METHODS The Chinese version was developed by using translation and back translation and was tested in Taiwan in 88 patients who had heart failure but no pulmonary disease or comorbid conditions limiting physical function. Data on a Taiwanese subsample (n=30) were compared with data on 30 patients in the United States matched by sex, age, and severity of disease to determine the equivalence of the Chinese and English versions. Construct validity was assessed by testing the hypothesis that health-related quality of life measured by using the Minnesota Living With Heart Failure Questionnaire is associated with the score on the dyspnea questionnaire. Reliability was assessed by using the Cronbach alpha and item-total correlations. RESULTS Equivalence between the US and Taiwanese samples was high, from 0.67 to 0.91 for each item of the questionnaire and for the total score. Satisfactory correlations between the Chinese dyspnea and the Minnesota questionnaires, especially in the physical dimension (r=0.71, P<.001), provided support for the construct validity of the Chinese questionnaire. Reliability of the Chinese questionnaire was adequate (alpha=0.94). CONCLUSIONS The Chinese Modified Pulmonary Functional Status and Dyspnea Questionnaire is a reliable and valid measure for dyspnea that can be used in Taiwanese patients with heart failure.