Cross-cultural adaptation: translation and content validation of the Brazilian version of the international fitness scale instrument

Abstract

OBJECTIVE: To perform the cross-cultural adaptation through translation, content validation, clarity and comprehension of the International Fitness Scale (IFIS) questionnaire. METHODS: The cross-cultural adaptation of the IFIS was performed through the following steps: translation, translation synthesis, back-translation, back-translation synthesis and review by a committee of experts (n=5), followed by the assessment of comprehension and clarity by 25 health professionals and the application of the instrument to adolescents (n=40). To evaluate the construct that the instrument proposes to measure, as well as the quality of the translation, descriptive analyses and the Content Validity Coefficient (CVC) were performed. To verify the degree of internal consistency of the questions, Cronbach’s alpha coefficient was used. RESULTS: After the experts’ evaluation, only the item (title) presented a value below 80% on the five-point Likert scale, regarding idiomatic (3.40) and conceptual (3.80) equivalence. After the requested adjustments, the final version of the questionnaire presented a total CVC of 0.94. The degree of clarity and comprehension assessed by health professionals ranged from 4.5 to 5.0, and a CVC of 0.95. The total Cronbach’s alpha was 0.88, which is equivalent to high internal consistency. CONCLUSION: The cross-cultural adaptation proved to be valid, presenting both quality of content and clarity and comprehension, in addition to being ready to move on to the next psychometric analyses, which will allow future recommendations for its application and assessment of physical fitness of adolescents in Brazil.