Translation and psychometric properties of the Danish version of the Myocardial Infarction Dimensional Assessment Scale (MIDAS) among patients undergoing PCI

Abstract Purpose The Myocardial Infarction Dimensional Assessment Scale (MIDAS) is a 35-item instrument developed for patients with myocardial infarction, but has not yet been evaluated in a Danish setting. The aim of this study was to translate and assess the psychometric properties of the Danish version of the MIDAS scale in patients with acute coronary syndromes or stable angina pectoris receiving percutaneous coronary intervention (PCI). Methods This cross-sectional psychometric evaluation used two-month follow-up data from adult patients enrolled in the CONCARD PCI study. MIDAS was translated, culturally adapted, and pretested before use. Further questionnaires included assessment of angina (SAQ-7). symptoms of anxiety and depression (HADS) and physical and mental health status (RAND-12) linked with sociodemographic and clinical characteristics collected at baseline. Construct validity was evaluated through CFA and hypotheses testing, including known-groups analyses and correlations with SAQ-7, HADS, and RAND-12. Internal consistency was assessed using Cronbach’s alpha. Results A total of 1447 patients were included: the median age was 67 years (IQR 57–74), and 22% were women. The CFA, based on 1051 participants with complete MIDAS data, did not adequately support the original seven-factor structure (χ²(539) = 4409, p < 0.001; RMSEA = 0.083; TLI = 0.833; CFI = 0.849). Standardized factor loadings ranged from 0.48 to 0.88. Three of six predefined known-groups hypotheses were supported (50%). Correlations for the expected convergent relationships were moderate to high, and domain-level Cronbach’s alpha values ranged from 0.67 to 0.93. Conclusion The findings generally supported convergent validity and domain-level internal consistency, whereas the known-groups analyses provided limited support, and the original seven-factor structure was not adequately supported.