Abstract
INTRODUCTION: The Fear of Pain Questionnaire (FOPQ) is a self-report tool designed to measure an individual's fear of pain (FOP). While the Persian version of the FOPQ (FOPQ-P) has been developed, its validity and reliability have not yet been assessed in the Iranian context. This study aims to evaluate the psychometric properties of the FOPQ-P among Iranian patients after surgery. METHODS: A methodological study was conducted in 2023 involving 400 post-surgery patients selected with a convenience sampling. The FOPQ was translated into Persian, and its psychometric properties were analyzed using network analysis, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), as well as assessments of convergent and discriminant validity. Internal consistency was measured using Cronbach's alpha, McDonald's Omega, average inter-item correlation coefficient, Composite Reliability, and Maximal Reliability. RESULTS: The EFA results with Promax and Kaiser Normalization rotation identified two factors that explained 54.32% of the variance, comprising seven items. The CFA confirmed the model's validity. Both convergent and discriminant validity were established. The reliability analyses showed that Cronbach's alpha, McDonald's omega, composite reliability, and MaxR for all constructs were above 0.7. Additionally, the average inter-item correlation coefficient was greater than 0.5, indicating strong internal consistency and construct reliability. CONCLUSION: The findings suggest that the FOPQ-P possesses a valid structure and was acceptable reliability in patients cultural context of Iran post-surgery, making it a suitable instrument for measuring fear of pain in this population.