Geriatric Pain Measure: Cross-Cultural Adaptation and Psychometric Properties of the Persian Version of Geriatric Pain Measure (P-GPM) among Elderly Adults

Background: Chronic pain is a common issue among older adults that affects not only their physical health but also their psychological well-being and functional abilities. Accurate pain assessment is essential, requiring multidimensional tools adapted to the cultural context of the target population. This study aimed to translate, culturally adapt, and evaluate the psychometric properties of the Persian version of the Geriatric Pain Measure (GPM-24) in Iranian older adults. Methods: This methodological study was conducted in 2025 with a sample of 290 individuals aged 60 years and above living in Sari, Iran. The GPM-24 was translated into Persian and psychometrically tested. Additional tools used included a demographic questionnaire, the McGill Pain Questionnaire (MPQ), the Visual Analogue Scale (VAS), and the Timed Up and Go (TUG) test. Data analysis was performed using SPSS and the lavaan package in R, with significance set at p < 0.05. Results: Participants’ mean(SD) age was 69.45(6.47) years. Face and content validity were confirmed with a content validity ratio (CVR) of 75%. Confirmatory factor analysis supported a five-factor structure of the Persian GPM-24, showing acceptable fit indices (χ²/df=1.10, CFI=0.91, RMSEA=0.07). Significant correlations between GPM scores and MPQ (r=0.64), VAS (r=0.85), and TUG (r=0.39) indicated good convergent validity. Reliability was excellent, with Cronbach’s alpha of 0.84 and intraclass correlation coefficient (ICC) of 0.98. Linear regression revealed that age, education, and gender significantly predicted GPM scores (p < 0.05). Conclusion: The Persian GPM-24 demonstrates good validity and reliability and is a suitable tool for assessing multidimensional pain in Iranian older adults.