Validation of the Persian version of dysphagia in multiple sclerosis questionnaire for the assessment of dysphagia in multiple sclerosis
Background: About one third of patients with multiple sclerosis (MS) experience dysphagia. Dysphagia can cause complications such as malnutrition, lung infections, aspiration pneumonia and dehydration, thus it is very helpful to diagnose dysphagia as soon as possible. The aim in this study was to translate dysphagia in multiple sclerosis (DYMUS) questionnaire into Farsi and and validate it.
Methods: Forward-backward method was used to translate original English version of DYMUS into farsi, and then the questionnaire (one for each patient) was filled in through asking questions from 200 patients with MS by a speech and language pathologist. Confirmatory factor analysis (CFA) was used to examine the construct validity. Internal consistency and test-retest reliability of the DYMUS were evaluated using Cronbach’s alpha and the intraclass correlation coefficient (ICC), respectively.
Results: CFA showed that a two-factor model of DYMUS including “dysphagia for solid” and “dysphagia for liquid” fitted the data well [relative chi-square [χ2/degree of freedom (df) = 1.55, CFI = 0.967, Tucker-Lewis index (TLI) = 0.957, root mean square error of approximation (RMSEA) = 0.053, and weighted root mean square residual (WRMR) = 0.874]. The Cronbach’s alpha for total score and liquid and solid subscales were 0.776, 0.557, and 0.725, respectively. The DYMUS showed adequate test-retest reliability for the total and subscales (ICC: 0.880-0.956). Moreover, this study has shown a significant relationship between DYMUS score and Expanded Disability Status Scale (EDSS) score, disease duration, type of MS, and self-reported dysphagia.
Conclusion: The Persian version of DYMUS is a reliable and valid tool to screen dysphagia among patients with MS.
2. Burks JS, Johnson KP. Multiple sclerosis: Diagnosis, medical management, and rehabilitation: Diagnosis, medical management, and rehabilitation. New York, NY: Demos Medical Publishing; 2000. p. 486-7.
3. Sales DS, Alvarenga RM, Vasconcelos CC, Silva RG, Thuler LC. Translation, cross-cultural adaptation and validation of the Portuguese version of the DYMUS questionnaire for the assessment of dysphagia in multiple sclerosis. Springerplus 2013; 2: 332.
4. Poorjavad M, Derakhshandeh F, Etemadifar M, Soleymani B, Minagar A, Maghzi AH. Oropharyngeal dysphagia in multiple sclerosis. Mult Scler 2010; 16(3): 362-5.
5. Calcagno P, Ruoppolo G, Grasso MG, De Vincentiis M, Paolucci S. Dysphagia in multiple sclerosis prevalence and prognostic factors. Acta Neurol Scand 2002; 105(1): 40-3.
6. Abraham SS, Yun PT. Laryngopharyngeal dysmotility in multiple sclerosis. Dysphagia 2002;17(1): 69-74.
7. Marchese-Ragona R, Restivo DA, Marioni G, Ottaviano G, Masiero S, Staffieri A. Evaluation of swallowing disorders in multiple sclerosis. Neurol Sci 2006; 27(4): s335-s337.
8. Thomas FJ, Wiles CM. Dysphagia and nutritional status in multiple sclerosis. J Neurol 1999; 246(8): 677-82.
9. Restivo DA, Marchese-Ragona R, Patti F. Management of swallowing disorders in multiple sclerosis. Neurol Sci 2006; 27(4): s338-s340.
10. Bergamaschi R, Crivelli P, Rezzani C, Patti F, Solaro C, Rossi P, et al. The DYMUS questionnaire for the assessment of dysphagia in multiple sclerosis. J Neurol Sci 2008; 269(1-2): 49-53.
11. Villain M, Heinzlef O. DYMUS questionnaire for dysphagia in multiple sclerosis: French validation and clinical considerations. Proceedings of the 29th Congress of the European Committee for Research and Treatment in Multiple Sclerosis (ECTRIMS) and the 18th Annual Conference of Rehabilitation in MS (RIMS); 2013 Oct 2-5; Copenhagen, Denmark.
12. Hu Lt, Bentler PM. Cutoff criteria for fitindexes in covariance structure analysis: Conventional criteria versus new alternatives. Struct Equ Modeling 1999; 6(1): 1-55.
13. Kline RB. Principles and practice of structural equation modeling. 2nd ed. New York, NY: Guilford Press; 2005.
14. Muthen L, Muthen B. Mplus User's Guide. Los Angeles, CA: Muthen and Muthen; 2012.
15. Bland JM, Altman DG. Cronbach's alpha. BMJ 1997; 314(7080): 572.
16. Nunnally JC, Bernstein IH. Psychometric theory. 3rd ed. New York, NY: McGraw-Hill; 1994.
17. Fernandes AM, Duprat AC, Eckley CA, Silva L, Ferreira RB, Tilbery CP. Oropharyngeal dysphagia in patients with multiple sclerosis: do the disease classification scales reflect dysphagia severity? Braz J Otorhinolaryngol 2013; 79(4): 460-5.
18. Bergamaschi R, Rezzani C, Minguzzi S, Amato MP, Patti F, Marrosu MG, et al. Validation of the DYMUS questionnaire for the assessment of dysphagia in multiple sclerosis. Funct Neurol 2009; 24(3): 159-62.