Psychometric Validation of a Japanese Version of the emPHasis-10 Questionnaire, a Patient-Reported Outcome Measure for Pulmonary Hypertension ― Multicenter Study in Japan ―

Background: The emPHasis-10 questionnaire is a disease-specific patient-reported outcome assessment of quality of life (QOL) in pulmonary hypertension (PH). The aim of this study was to psychometrically validate a linguistically validated Japanese version of the emPHasis-10. Methods and Results: Japanese patients with PH (age ≥18 years) and no change in functional status, or initiation or change in PH-specific treatment during the past 3 months were recruited from 5 institutions from August 2018 to July 2019. A set of questionnaires was administered twice. The validity and reliability of the emPHasis-10 were assessed using the data of 76 patients. On concurrent validity analysis, a moderate-to-strong correlation was seen with the total score of all 5 external criteria (the Minnesota Living with Heart Failure modified for PH [MLHFQ-PH], Hospital Anxiety and Depression Scale, Dyspnea-12 questionnaire, European Quality of Life-5 Dimensions questionnaire [EQ-5D], and 6-min walk test), with a notably strong correlation with the MLHFQ-PH (0.77) and EQ-5D (-0.64). On known-group validity, a linear increasing trend of the emPHasis-10 score was observed across 4 World Health Organization functional status groups (Jonckheere-Terpstra test, 1-sided, P<0.001). Intraclass correlation coefficient for test-retest reliability was 0.86, and the Cronbach's α for internal consistency was 0.89. Conclusions: The Japanese emPHasis-10 questionnaire is psychometrically valid to evaluate QOL in Japanese PH patients in a clinical setting.