Reliability and validity of the Korean version of the MacNew heart disease Health-related Quality of Life questionnaire

Background Myocardial infarction and unstable angina are prevalent in Korea. The MacNew Heart Disease health-related quality of life questionnaire is a widely used patient-reported outcome measure for patients with heart disease in several countries. In this study, we tested the validity and reliability of the Korean version of the MacNew (K-MacNew). Methods Participants were 200 patients who had experienced unstable angina or myocardial infarction, and were recruited from a tertiary hospital in Korea. The K-MacNew was developed using forward-backward translation techniques. Construct validity (including discriminative validity), concurrent validity, and internal consistency reliability of the K-MacNew were assessed. Discriminative validity was assessed by examining the between-group differences in the K-MacNew scores according to functional capacity, anxiety, and depression levels. Concurrent validity was examined by correlating the K-MacNew dimensions with the physical and mental health domains of the 36-item Short Form Health Survey Instrument (SF-36). Results Factor analysis results of the K-MacNew demonstrated a three-factor structure (emotional, physical, and social) that explained 57.92% of the variance. Significant differences in the K-MacNew scores were observed according to patients' functional capacity, anxiety, and depression levels. The SF-36 physical health domain score showed a moderate positive correlation with the physical dimension score of the K-MacNew (r = 0.517, P < 0.001), and the SF-36 mental health domain score showed a strong positive correlation with the emotional dimension of K-MacNew (r = 0.745, P < 0.001). The K-MacNew showed good internal consistency, with a Cronbach's alpha of 0.947 for the global scale. Conclusion The K-MacNew demonstrated good reliability and validity for use as a patient-reported outcome measure and is ready for the assessment of the health-related quality of life of patients with coronary artery disease in Korea. To establish the clinical validity of the K-MacNew, additional studies should be conducted to verify the validity and reliability of the K-MacNew in a number of participants, including those with various types of coronary artery disease.