Translation, cultural adaptation and validation of the Foot Function Index-revised (FFI-R)

K Stéfani,M.P Filho,P Rizzi,P Wun

doi:10.1016/j.fas.2017.07.1117

Abstract

Patient-reported outcome measures are a critical tool in evaluating the efficacy of orthopaedic procedures. The intention of this study was to develop and culturally adapt a German version of the Manchester-Oxford Foot Questionnaire (MOXFQ) and to evaluate reliability, validity and responsiveness.According to guidelines forward and backward translation has been performed. The German MOXFQ was investigated in 177 consecutive patients before and 6 months after foot or ankle surgery. All patients completed MOXFQ, Foot and Ankle Outcome Score (FAOS), Short form 36 and numeric scales for pain and disability (NRS). Test-Retest reliability, internal consistency, floor and ceiling effects, construct validity and minimal important change were analyzed.The German MOXFQ demonstrated excellent test-retest reliability with ICC values >0.9 Cronbach’s alpha (α) values demonstrated strong internal consistency. No floor or ceiling effects were observed. As hypothesized MOXFQ subscales correlated strongly with corresponding FAOS and SF-36 domains. All subscales showed excellent (ES/SRM >0.8) responsiveness between preoperative assessment and postoperative follow-up.The German version of the MOXFQ demonstrated good psychometric properties. It proofed to be a valid and reliable instrument for use in foot and ankle patients.

Highlights

The use of assessment scales in scientific studies is an essential requirement for the comparison of different treatments in patients with the same diagnosis.[1,2,3,4,5,6,7,8,9] The majority of outcome assessment scales are developed in English and directed at patients who speak this particular language
After the unidimensionality of the Foot Function Index - Revised” (FFI-R) was confirmed by an analysis of its subscales, responses were coded into four categories for ease of use
The translation and cultural adaptation processes were carried out in five stages, as recommended by the literature:[10,11,17] a) stage 1: the FFI-R was first translated to Portuguese by two independent Brazilian translators, one of whom was an official translator, while the other was a technical translator with expertise in health care

Summary

Introduction

The use of assessment scales in scientific studies is an essential requirement for the comparison of different treatments in patients with the same diagnosis.[1,2,3,4,5,6,7,8,9] The majority of outcome assessment scales are developed in English and directed at patients who speak this particular language As a result, they must be translated and culturally adapted in order to be used in any other country. The FFI was developed to measure the impact of the pain, disability and activity restriction associated with foot pathology on patient functioning It is a self-administered instrument composed of 23 items divided into three subscales.[1,13,14,15] The FFI has already been translated, culturally adapted and validated for use in Brazilian Portuguese.[16] The FFI-R was developed at a later date in response to criticism of the original scale.

Methods

Discussion

Conclusion