Cross-cultural adaptation and validation of the Foot and Ankle Outcome Score (FAOS) into Spanish (Chile)

Abstract

Purpose: To adapt and validate the English version of the Foot and Ankle Outcome Score (FAOS) into Spanish FAOS-CL, following the WHO guidelines.

Methods: A cross-sectional study including 318 outpatients with non-traumatic conditions. Validity, acceptability and internal consistency including correlations with the Medical Outcome Study Short Form 36 are reported.

Results: The preliminary version resulted from the forward and back-translation and a pilot administration. Validation response rate was 99.22%. Substantial ceiling effects were observed for Symptoms and ADL and floor effect for QoL sub-scales. The FAOS-CL had excellent internal consistency (Cronbach's α = 0.98). The principal component analysis gave five factors explaining the 72.6% of the variance. The FAOS-CL items significantly correlate with their sub-scales. FAOS-CL sub-scales significantly correlated with SF-36 components and subcomponents.

Conclusion: The first Spanish version of the FAOS was generated. Culturally adapted and validated with high reliability capable of evaluating different foot and ankle conditions.

Keywords: Cross-cultural adaptation; Orthopaedic condition; PROMs; Psychometric evaluation; Spanish.