Validation of myasthenia gravis activity of daily living questionnaire: Persian version

Background: The 8-item myasthenia gravis activity of daily living (MG-ADL) questionnaire is a valid and reliable instrument for evaluating myasthenia gravis (MG)-associated disability. This study aims to assess its validity and reliability in the Iranian population. Methods: A total number of 58 patients with MG were qualified for the examination. All 58 patients completed the Persian translation of 15-item Myasthenia Gravis Quality of Life (MG-QOL15) and MG-ADL questionnaires initially, and 30 filled out the MG-ADL questionnaire 2 to 4 weeks after the initial visit. Pearson correlation coefficient of questionnaires, internal consistency using Cronbach's alpha (α), and test-retest repeatability of the questionnaire were evaluated. Results: The Pearson correlation coefficient of Persian versions of MG-QOL and MG-ADL was 0.93 (P < 0.01). The Persian MG-ADL showed satisfactory internal consistency (Cronbach’s α = 0.89) and test-retest reliability (r = 0.99, P < 0.01). Conclusion: The Persian MG-ADL is a valid and reliable questionnaire for the determination of activities of daily life in Iranian patients with MG.