Document Type : Original Article


1 Department of Neurology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran

2 Iranian Center of Neurological Research, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran


Background: Neuromuscular disorders affect physical and mental aspects of a patient and in other words alter the patients’ quality of life (QOL). In the present study, we investigated the validity and reliability of the Persian version of Individualized Neuromuscular QOL (INQOL) to provide a better insight into patients’ QOL.
Methods: Original version of the INQOL was translated backward and then forward. The resultant Persian version and a standard questionnaire, 36-Item Short Form Health Survey (SF-36), were then given to 83 participants with neuromuscular disorders. Internal consistency, known-group validity, concurrent validity, and test-retest reliability were assessed.
Results: The scores of matched sections for QOL in the two questionnaires were favorably correlated (P < 0.05). Correlation between test and retest scores was also significant (P < 0.05). Moreover, the Cronbach’s alpha of 0.82 was representative of robust internal consistency between INQOL covering sections.
Conclusion: The Persian version of the INQOL can be used in clinical and research practice to detect changes in QOL which are related to neuromuscular disorders, due to its favorably reliable and valid characteristics.


  1. Emery AE. The muscular dystrophies. Lancet 2002; 359(9307): 687-95.
  2. Burns TM, Graham CD, Rose MR, Simmons Z. Quality of life and measures of quality of life in patients with neuromuscular disorders. Muscle Nerve 2012; 46(1): 9-25.
  3. Boyer F, Morrone I, Laffont I, Dizien O, Etienne JC, Novella JL. Health related quality of life in people with hereditary neuromuscular diseases: An investigation of test-retest agreement with comparison between two generic questionnaires, the Nottingham health profile and the short form-36 items. Neuromuscul Disord 2006; 16(2): 99-106.
  4. Dallmeijer AJ, Dekker J, Knol DL, Kalmijn S, Schepers VP, de Groot V, et al. Dimensional structure of the SF-36 in neurological patients. J Clin Epidemiol 2006; 59(5): 541-3.
  5. Coons SJ, Rao S, Keininger DL, Hays RD. A comparative review of generic quality-of-life instruments. Pharmacoeconomics 2000; 17(1): 13-35.
  6. Vincent KA, Carr AJ, Walburn J, Scott DL, Rose MR. Construction and validation of a quality of life questionnaire for neuromuscular disease (INQoL). Neurology 2007; 68(13): 1051-7.
  7. Sansone VA, Panzeri M, Montanari M, Apolone G, Gandossini S, Rose MR, et al. Italian validation of INQoL, a quality of life questionnaire for adults with muscle diseases. Eur J Neurol 2010; 17(9): 1178-87.
  8. Sadjadi R, Vincent KA, Carr AJ, Walburn J, Brooks VL, Pandya S, et al. Validation of the individualised neuromuscular quality of life for the USA with comparison of the impact of muscle disease on those living in USA versus UK. Health Qual Life Outcomes 2011; 9: 114.
  9. Seesing FM, van Vught LE, Rose MR, Drost G, van Engelen BG, van der Wilt GJ. The individualized neuromuscular quality of life questionnaire: Cultural translation and psychometric validation for the Dutch population. Muscle Nerve 2015; 51(4): 496-500.
  10. Fagoaga J, Girabent-Farres M, Bagur-Calafat C. Translation and validation of the Individualised Neuromuscular Quality of Life scale for the Spanish population: Quality of life assessment for persons with neuromuscular diseases. Rev Neurol 2017; 64(5): 194-200. [In Spanish].
  11. Peric S, Sansone VA, Lavrnic D, Meola G, Basta I, Miljkovic M, et al. Serbian validation of the Individualized Neuromuscular Quality of Life Questionnaire (INQoL) in adults with myotonic dystrophy type 1. J Neurol Res 2011; 1(4): 153-60.
  12. Montazeri A, Goshtasebi A, Vahdaninia M, Gandek B. The Short Form Health Survey (SF-36): Translation and validation study of the Iranian version. Qual Life Res 2005; 14(3): 875-82.
  13. Mathieu J, Boivin H, Meunier D, Gaudreault M, Begin P. Assessment of a disease-specific muscular impairment rating scale in myotonic dystrophy. Neurology 2001; 56(3): 336-40.
  14. Walton JN, Gardner-Medwin D. Progressive muscular dystrophy and myotonic disorders. In: Walton JN, editor. Disorders of voluntary muscle. 4th ed. Edinburgh, UK: Churchill Livingstone; 1981. p. 481-524.
  15. Tavakol M, Dennick R. Making sense of Cronbach's alpha. Int J Med Educ 2011; 2: 53-5.
  16. Fujino H, Saito T, Takahashi MP, Takada H, Nakayama T, Ogata K, et al. Validation of The Individualized Neuromuscular Quality of Life in Japanese patients with myotonic dystrophy. Muscle Nerve 2018.
  17. Mukaka MM. Statistics corner: A guide to appropriate use of correlation coefficient in medical research. Malawi Med J 2012; 24(3): 69-71.
  18. Meola G, Sansone V. Cerebral involvement in myotonic dystrophies. Muscle Nerve 2007; 36(3): 294-306.
  19. Thornton CA. Myotonic dystrophy. Neurol Clin 2014; 32(3): 705-19.
  20. Lovering RM, Porter NC, Bloch RJ. The muscular dystrophies: From genes to therapies. Phys Ther 2005; 85(12): 1372-88.