Validation of the Barthel Index in elderly patients attended in outpatient clinics, in Brazil

Objective: To validate the Barthel Index for elderly patients being attended in outpatient clinics in Brazil through analysis of reliability and validity. Methods: To prove the reliability, it was used the internal consistency and to verify its validity was used the factor analysis and the validity criterions of convergence and discriminancy. Results: The reliability calculated with the alpha of Cronbach presented the value of 0.90 for the total scale. The validity analysis of convergent criterion, using the Functional Independence Measure, identified a satisfactory correlation for most areas. In the factor analysis, which retained only one domain and the 10 items of the original scale, the variance explained was 63.8%. Conclusion: The results recommend its use for evaluating the functional ability of elderly patients being treated in outpatient care in Brazil.