Filipino Translation, Cross-Cultural Adaptation and Validation of the American Orthopedic Foot and Ankle Society’s (AOFAS) Ankle-Hindfoot Scale

Abstract

Background. Injuries about the foot and ankle account for a significant number of injuries that may lead to substantial functional impairment and disability. A standardized method of outcome assessment is necessary to evaluate and monitor patients’ progress. One commonly used evaluation system is the American Orthopedic Foot and Ankle Society (AOFAS) Ankle and hindfoot scale. The purpose of this study was to translate the AOFAS Ankle-Hindfoot scale into Filipino and establish its cultural adaptation and validity. Methodology. This was a single-center cross-sectional study that included patients with ankle and hindfoot conditions who took part in the evaluation of the proposed Filipino translation of the Ankle-Hindfoot Scale, following the guidelines set by the AOFAS. Construct validity and test-retest reliability were analyzed using intra-class correlation coefficients; internal consistency was analyzed with Cronbach’s alpha. A Rasch principal components analysis was also used to test for reliability and construct validity. Results. Cronbach’s alpha was measured at 0.98 in terms of function, while the item separation index showed good internal consistency of the construct. Rasch analysis confirmed that the construct is a multidimensional metric. Intra-class correlation using Pearson’s coefficient was significant at 0.8779 (p <0.05), showing good test-retest reliability, while convergent validity confirmed a strong positive correlation between the overall AOFAS score and the health perception domain of the Medical Outcomes Study Questionnaire Short Form-36 (SF-36 v2) (Tagalog) (Pearson = 0.647). Conclusions. The Filipino translation of the AOFAS Ankle-Hindfoot Scale was successfully translated and culturally adapted to Filipino patients, with good internal consistency. We have likewise demonstrated a good correlation against a general health outcome measure (SF-36 v2) in terms of change in health perception and role limitation (physical).

Keywords

• AOFAS,
• ankle and hindfoot
• validation
• cultural adaptation
• Filipino