Cross-cultural adaptation of the Gross Motor Function Classification System into Brazilian-Portuguese (GMFCS).

Background: Due to the complexity of clinical symptoms of cerebral palsy and the difficulties in classifying it based upon the motor types and the topography of the body distribution only, Canadian researchers have proposed the Gross Motor Function Classification System (GMFCS). Although this classification system has been largely used in Brazil, it has not been cross culturally adapted yet.

Objectives: To perform the cross adaptation of the Gross Motor Function Classification System for the Cerebral Palsy (GMFCS) into Brazilian-Portuguese and to verify the reliability among observers of the adapted instrument in Brazilian children.

Methods: This study was performed in two stages; the first stage was related to the process of cross-cultural adaptation and the second stage tested the instrument. Translation, back-translation, semantic and content analysis, back-translation of the final version and the approval of the authors were used for the cross-cultural adaptation. The test of the instrument was performed in 40 children with cerebral palsy, who were evaluated by two raters to verify the reliability among the observers.

Results: The results showed that the stages of translation and back-translation did not present any difficulties and the semantic and conceptual equivalence was achieved. The reliability among the observers showed that the evaluations do not differ and that there is an excellent correlation and internal consistency of the construct with an ICC of 0.945 (95% CI 0.861 to 0.979) and a Cronbach a of 0.972.

Conclusions: The final version of the GMFCS showed good potential of applicability for undergraduate students and professionals of the neuropediatric area.