Filipino Translation and Cross-Cultural Adaptation of the Lower Extremity Functional Scale

Aim: To translate, cross-culturally adapt, and validate the Lower Extremity Functional Scale to Filipino. Methods: In this cross-sectional validation study, the Lower Extremity Functional Scale was translated and cross-culturally adapted to Filipino using the guidelines for cross-cultural adaptation of self-report measures by Beaton et al. and Sousa and Rojjanasrirat. The pre-final version of the Filipino Lower Extremity Functional Scale (FIL-LEFS) underwent online pilot testing (n = 11) among Filipinos across the Philippines who have musculoskeletal conditions. This was to ensure that the scale and item questions were clear and comprehensible. Subsequently, the experts' committee determined the psychometric properties of face validity using FVI and content validity using CVI and COSMIN criteria and rating system. Results: The FIL-LEFS used Filipino terms that are understandable to Filipinos of all ages with lower extremity conditions. The Face Validity Index scores showed that all items were acceptable (> 0.80). In addition, the content validity was rated excellent (S-CVI Ave > 0.90), with all items indicating relevance and acceptability. The COSMIN content validation further showed that the study was of moderate quality in terms of sufficient content validity as rated by five experts and inconsistent content validity as rated by four experts. Conclusion and Implications: The translation and cultural adaptation of LEFS was successful. The pilot testing results showed that the FIL-LEFS is a valid tool in measuring difficulty in functional activities involving the lower extremity. However, there is still a need to establish its full psychometric properties.