Measurement properties of the Brazilian version of the Motor Assessment Scale, based on Rasch analysis

Purpose: To cross-culturally adapt and verify the measurement properties of the Brazilian version of the Motor Assessment Scale (MAS). Methods: The process of cross-cultural adaptation followed standardized procedures. Construct validity of the MAS was investigated using Rasch analysis (n = 100), whereas inter-rater and test-retest reliabilities were evaluated using Kappa coefficients and Bland and Altman plots (n = 52). Results: The MAS demonstrated satisfactory measurement properties. The Kappa coefficients for the inter-rater and test-retest reliabilities were 0.73 (ranging from 0.79 to 1.00) and 0.82 (ranging from 0.86 to 1.00), respectively. The Bland and Altman plots showed adequate inter-rater and test-retest agreements. No ceiling or floor effects were observed and only one item exhibited misfit to the Rasch model expectations. Item 4 "sitting to standing" exhibited marginal misfit (infit MnSq = 1.44; Zstd = 2.6), but it did not affect the unidimensionality of the scale. Conclusions: The MAS demonstrated good indicators of validity and reliability to be used for the assessment of motor function of individuals with stroke within clinical and research contexts.