Disabilities of the arm, shoulder and hand (DASH): factor analysis of the version adapted to Portuguese/Brazil.

PURPOSE To investigate the psychometric properties (construct and discriminant validities) of the translated and validated version of DASH for the Portuguese language. METHOD Methodological study included 309 subjects with chronic or acute upper limb injury divided into two groups: acute and chronic. The Factor Analysis (principal components) was carried out to examine the construct structure of the DASH and discriminant function to determine the items that best predict individuals classified into chronic and acute groups. RESULTS Group A presented a higher DASH score average (71.8, SD = 15.6); the average score for the overall sample was 52.6 (SD = 26.3). The Kaiser Meyer Olkin and Bartlett Test of Sphericity demonstrated satisfactory suitability of the data to factor analysis, which identified three factors with Cronbach alpha indices ranging between 0.77 and 0.94, explaining 59% of the variance in the overall sample. The discriminant analysis adequately classified 93% of the cases regarding the group of origin and identified 11 variables with a discriminating power between the acute and chronic groups. CONCLUSIONS The DASH version adapted to Portuguese/Brazil proved to be a valid measure to document disability in the sample used for the present study. Specific items were identified as best predictors of chronic and acute group allocation.