EFAS Score - validation of the Norwegien version by the Score Committee of the European Foot and Ankle Society (EFAS).

BACKGROUND: The Score Committee of the European Foot and Ankle Society (EFAS) developed, validated, and published the EFAS Score in 16 languages. Currently, the Norwegian version completed data acquisition and was further validated.

METHODS: The data were collected pre-operatively and post-operatively at a minimum follow-up of 3 months and mean follow-up of 6 months. Item reduction, scale exploration, confirmatory analyses and responsiveness were performed using classical test theory and item response theory.

RESULTS: The internal consistency was confirmed in the Norwegian version (Cronbach's Alpha 0.86). The Standard Error of Measurement (SEM) was 0.31 and is similar to other language versions. Between baseline and follow-up, 77% of patients showed an improvement on their EFAS score, with good responsiveness (effect size 1.05).

CONCLUSIONS: The Norwegian EFAS Score version was successfully validated in patients with a wide variety of foot and ankle pathologies. All score versions are freely available at www.efas.net.