American Orthopaedic Foot and Ankle Society ankle-hindfoot scale: A cross-cultural adaptation and validation study from Iran.

BACKGROUND: The use of valid and reliable outcome rating scales is essential for evaluating the result of different treatments and interventions. The purposes of this study were to translate and culturally adapt the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale (AOFAS-AHFS) into Persian languages and evaluate its psychometric properties.

METHODS: Forward-backward translation and cultural adaptation method were used to develop Persian version of AOFAS-AHFS. From March to July 2016, one hundred consecutive patients with ankle and hindfoot injuries were included. Internal consistency and reproducibility were evaluated using Cronbach's alpha, Spearman's rank correlation coefficient and Intraclass correlation coefficient (ICC) respectively. Construct validity reported which compare the outcome rating scale measurements with Short Form-36 (SF-36), also convergent and discriminant validity evaluated using Spearman's rank correlation coefficient.

RESULTS: Mean age (SD) of the patients was 41.95±13.45years. Cronbach's α coefficient, Spearman's rho and ICC values were 0.71, 0.89 and 0.90 respectively. Total score of AOFAS-AHFS and SF-36 domains has a correlation ranged between 0.17-0.55. Spearman's rank correlation coefficient of 0.4 was exceeded by all items with the exception of stability. The Spearman's rank correlation between each item in functional subscales with its own subscales was higher than the correlation between these items and other subscales.

CONCLUSIONS: Persian version of AOFAS-AHFS provides additional reliable and valid instrument which can be used to assess broad range of patients with foot and ankle disorders that speaking in Persian. However, it seems that the original version of AOFAS-AHFS needs some revisions.