OBJECTIVES: The aims of the current study were 1) to evaluate the reliability and validity of the Brazilian version of the 15-item Myasthenia Gravis Quality of Life Scale and 2) to investigate the quality of life of Brazilian patients with myasthenia gravis and its determinants. METHODS: This cross-sectional study included 69 patients with myasthenia gravis who underwent neurological evaluation and completed questionnaires regarding quality of life (the 36-item Short Form of the Medical Outcomes Study and the 15-item Myasthenia Gravis Quality of Life Scale), anxiety and depressive symptoms. RESULTS: The Brazilian version of the 15-item Myasthenia Gravis Quality of Life Scale showed high internal consistency and good concurrent validity with the 36-item Short Form of the Medical Outcomes Study and its subscales. Determinants of quality of life in Brazilian patients with myasthenia gravis included the current status of myasthenia gravis as assessed by the Myasthenia Gravis Composite, the current prednisone dose and the levels of anxiety and depression. CONCLUSION: The Brazilian version of the 15-item Myasthenia Gravis Quality of Life Scale is a valid instrument. Symptom severity, prednisone dosage and anxiety and depression levels impact the quality of life of patients with myasthenia gravis.

Objetivo Realizar a tradução e a adaptação transcultural do “Questionário de Qualidade de Vida Específico para Miastenia Gravis – 15 itens” (MG-QOL15). Método Inicialmente, foi realizada a tradução do instrumento original em inglês para o português. Esta versão foi revisada e retrotraduzida para o inglês. A versão retrotraduzida foi comparada à versão original em inglês, sendo corrigidas as divergências no texto em português. Em um segundo momento, dez pacientes com MG acompanhados na Clínica de Doenças Neuromusculares do Hospital das Clínicas da Universidade Federal de Minas Gerais responderam ao questionário. Na aplicação do questionário, os itens mal compreendidos foram analisados pelos autores. Resultados Os itens 8, 13 e 15 foram considerados de difícil compreensão e modificados na versão final em português. A maioria dos pacientes (70%) apresentou uma pontuação total superior a 25, sendo que os itens 3, 8 e 9 apresentaram os escores mais elevados. Conclusão A versão brasileira do MG-QOL15 é um instrumento promissor para a avaliação de pacientes brasileiros com MG.

Objective To translate and to perform the cross-cultural adaptation of the “Questionnaire of Life Quality Specific for Myasthenia Gravis - 15 items” (MG-QOL15). Method The original English version of the questionnaire was translated into Portuguese. This version was revised and translated back into English. Later, both English versions were compared and the divergences were corrected in the Portuguese text. At a second stage, ten patients with MG followed at the Neuromuscular Diseases Clinic from the University Hospital, Universidade Federal de Minas Gerais answered the questionnaire. The authors analyzed the difficulties and misunderstandings in the application of the questionnaire. Results The questions 8, 13 and 15 were considered difficult to understand and were modified in the final Portuguese version. Most patients (70%) had a total score above 25, and the statements 3, 8 and 9 showed the highest scores. Conclusion The Brazilian version of the questionnaire MG-QOL15 seems to be a promising tool for the assessment of Brazilian patients with MG.