Objective: To perform a psychometric evaluation of the Myocardial Infarction Dimensional Assessment Scale (MIDAS) in Chinese patients with coronary heart disease.
Design and setting: Patients with angina (n=162), MI (n=124) or heart failure (n=95) were recruited from a regional university-affiliated hospital. The Chinese version of the MIDAS (C-MIDAS), the Hospital Anxiety and Depression Scale (HADS) and the Short-Form 36 Health Survey (SF-36) were administered to all patients at baseline and the C-MIDAS was also administered seven day (n=92) and three months (n=363) later.
Results: The C-MIDAS conforms to the 7-factor structure as proposed in the original version. It is reliable with Cronbach's alphas from 0.73 to 0.94 and test-retest reliabilities from 0.76 to 0.92. Four of its subscales (physical activity, insecurity, emotional reaction and dependency) correlated significantly with the SF-36 and the HADS in each diagnostic group and had good discriminative properties in terms of gender, emotional disturbance and perceived health deterioration, with responsiveness supported by medium-high effect sizes (0.43-0.83) and standardize response means (0.46-0.82). The other three subscales measuring treatment-related impacts added little to the validity and responsiveness of the C-MIDAS.
Conclusion: To render the C-MIDAS a core health-related quality of life measure for Chinese-speaking patients with coronary heart disease, further studies need to clarify the content adequacy and cultural relevancy of those subscales measuring treatment-related impact.