Validity analisys of the 10 meters walk timed test for quantification of motor function in patients with Duchenne muscular Dystrophy (DMD)

• Grant number: 12/25157-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2013
• End date: December 31, 2013
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Cláudia Ferreira da Rosa Sobreira
• Grantee: Marjory Irineu Bená
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Duchenne muscular dystrophy (DMD), a hereditary disease linked to the X chromosome, is characterized primarily by progressive degeneration of skeletal muscle due to the absence of the protein dystrophin. The progressive muscle weakness associated with the disease causes a decline in functional capacity. In this context, the 10 meters walk timed test has been used both in the clinical setting as well as in clinical research, to detect changes in functional capacity. The aim of this study is to analyze the following parameters related to the 10 meters walk timed test: intra-rater (test-retest) and inter-rater reliability; convergent construct validity; sensitivity to change in functional capacity. Thirty subjects will be enrolled in the study: 15 boys with a confirmed diagnosis of DMD and 15 age-matched healthy control boys. The reliability will be analyzed through the reproducibility of the measurements obtained by the same examiner and by different examiners, by calculating the intraclass correlation coefficient (ICC) and the standard error of measurement. Functional capacity will also be assessed with the Vignos scale and the Motor Function Measure (MFM) to allow for construct convergent validity analysis using either Pearson or Spearman's correlation coefficients (depending on whether the results present or not a normal distribution). The sensitivity to change will be evaluated with the reapplication of the 10 meters walk timed test, the Vignos scale, and the MFM after 6 to 12 months. The changes will be analyzed using the t-test or Mann-Whitney test (depending on whether the results present or not a normal distribution). With this study, we expect to define whether the 10 meters walk timed test is an appropriate tool for the identification of disease progression both in the routine follow-up evaluation as well as in clinical research.(AU)