Cross-cultural Adaptation, Validity, and Reliability of the Persian Version of Back Pain and Body Posture Evaluation Instrument for Adults

Background and Objectives: Back pain and neck pain are prevalent health concerns, emphasizing the importance of identifying effective risk factors for prevention. This study aimed to cross-culturally adapt and validate a tool assessing back and neck pain in adults, with a specific focus on body posture, to the Persian language. Methods: A methodological study was conducted involving forward and backward translation of the original English questionnaire into the Persian language. Face validity was evaluated with feedback from 30 participants, and content validity was determined using content validity ratio (CVR) and content validity index based on expert opinions from 10 physiotherapy specialists. A total of 237 participants were involved in the study, with 90 completing the questionnaire again after one week for test re-test reliability assessment. Results: The Persian version of the questionnaire demonstrated high content validity with a CVR above 0.6. The Persian version had suitable face validity. Test re-test reliability, assessed using percentage agreement and the Kappa coefficient, revealed satisfactory results, with all percentages above 70%. Notably, the intraclass correlation coefficient for questions 16 and 20 was 0.898 and 0.878, respectively. Conclusion: The Persian version of the tool exhibits high validity and reliability, making it a valuable instrument for use within the Persian-speaking community.