Psychometric properties of the repetitive thinking questionnaire among Iranian patients with heart disease: validity and reliability assessment

Repetitive negative thinking (RNT) is strongly associated with depressive symptoms, which are common among patients with heart disease. Psychological factors such as anxiety and RNT play a significant role in the overall distress experienced by individuals with heart disease. Worry and rumination are key components of psychological distress in these patients, ultimately leading to worse cardiovascular outcomes. The purpose of this study was to assess the psychometric properties of the Repetitive Thinking Questionnaire (RTQ) in Iranian patients with heart disease. A convenience sample of 400 Iranian adults with coronary artery disease, valvular abnormalities, heart muscle disorders, and heart failure were recruited from three medical settings: two cardiac departments in public hospitals and one private heart specialist’s clinic in Amol, Iran. The RTQ was translated, and its psychometric properties were evaluated through exploratory and confirmatory factor analysis. The internal consistency of the scales was assessed using Cronbach’s alpha and McDonald’s omega. The mean age of the participants was 42.95 years (SD = 14.02). An exploratory factor analysis identified a single factor explaining 60.65% of the variance in nine items. One item was removed due to communalities of less than 0.20 and factor loadings of less than 0.30. Confirmatory factor analysis supported the results from the exploratory analysis, and the internal consistency of the scale was considered acceptable. The study shows that the Persian translation of the RTQ produces psychometrically sound scores within the population of Iranian heart disease patients. Exploratory and confirmatory analyses supported a unidimensional factor structure with acceptable internal consistency. Measurement invariance across genders further supports the scale’s utility for comparative research within this population.