Reliability, validity and clinical applicability of the German version of the European Foot and Ankle Society Score

BACKGROUND: Purpose of this study was an external evaluation of the recently developed European Foot and Ankle Society (EFAS) Score.

METHODS: From July 2021 to January 2022, all consecutive patients with foot and ankle disorders were asked to complete three validated questionnaires prior to the medical examination. Validity was evaluated with correlations between the EFAS Score, Manchester-Oxford Foot Questionnaire (MOxFQ) and Foot and Ankle Outcome Score (FAOS). Cronbach's alpha, floor and ceiling effects and the minimal important difference (MID) were determined.

RESULTS: In a total of 161 included patients, the EFAS Score demonstrated a very good correlation with the MOxFQ index score (r = 0.76, p < 0.001). There were no floor or ceiling effects. Cronbach's alpha was 0.863, and the MID amounts 3 points and 7 points for significant changes respectively.

CONCLUSION: In terms of reliability and validity, the EFAS Score demonstrated good to excellent psychometric values. A change of 7 points or more in the EFAS Score in longitudinal examinations is clinically highly relevant.