Cross-cultural adaptation and validation of the Foot Function Index to Spanish.
BACKGROUND
The purpose of this study was to adapt and validate the Foot Function Index to the Spanish (FFI-Sp) following the guidelines of the American Academy of Orthopaedic Surgeons.


METHODS
A cross-sectional study 80 participants with some foot pathology. A statistical analysis was made, including a correlation study with other questionnaires (the Foot Health Status Questionnaire, EuroQol 5-D, Visual Analogue Pain Scale, and the Short Form SF-12 Health Survey). Data analysis included reliability, construct and criterion-related validity and factor analyses.


RESULTS
The principal components analysis with varimax rotation produced 3 principal factors that explained 80% of the variance. The confirmatory factor analysis showed an acceptable fit with a comparative fit index of 0.78. The FFI-Sp demonstrated excellent internal consistency on the three subscales: pain 0.95; disability 0.96; and activity limitation 0.69, the subscale that scored lowest. The correlation between the FFI-Sp and the other questionnaires was high to moderate.


CONCLUSIONS
The Spanish version of the Foot Function Index (FFI-Sp) is a tool that is a valid and reliable tool with a very good internal consistency for use in the assessment of pain, disability and limitation of the function of the foot, for use both in clinic and research.
University of Malaga, Spain.
Joaquin
J
Paez-Moguer
Loyola University Medical School, Maywood, IL, United States.
Elly
E
Budiman-Mak
University of Malaga, Spain; School of Clinical Sciences, Faculty of Health at the Queensland University of Technology, Australia. Electronic address: acuesta@uma.es.
Antonio I
AI
Cuesta-Vargas
D000328:Adult; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D005260:Female; D005534:Foot Diseases / Q000175:diagnosis*; D006801:Humans; D008297:Male; D011795:Surveys and Questionnaires
Foot Health Status; Patient report outcomes; Questionnaire; Reliability; Validity