Development and Validation of a Scale to Measure Fear of ACTivity in Patients with Coronary Artery Disease – (Fact-CAD)

Abstract Objective To develop and validate a scale to measure fear of activity in patients with coronary artery disease. Design Psychometric study. Setting Outpatient cardiology clinics. Participants The scale was applied to 250 patients who had myocardial infarction, coronary artery bypass grafting or percutaneous coronary intervention within the last 12 months. Interventions A scale for Fear of ACTivity in patients with CAD (Fact-CAD) was created through semi-structured focus group interviews with patients. Face and content validity of Fact-CAD was verified. Main Outcome Measures Psychometric analysis included model fit, unidimensionality, reliability, local dependency, differential item functioning and external construct validity. Analyses were performed using the Rasch Analysis Model. Results Fact-CAD scale was a reliable (high Person Separation Index of 0.89) and valid (unidimensional, no misfit, local independency supported, no residual correlations) measure of fear of activity. Three items showed differential item functioning according to employment status, marital status and angina pectoris, which were not assigned as real item bias by experts and remained in the model. Conclusion Fact-CAD was supported by Rasch analysis as a psychometrically valid scale to evaluate fear of activity in patients with coronary artery disease.