The self-report Barthel Index: preliminary validation in people with Parkinson's disease

Background and purpose: To make a preliminary assessment of the reliability and validity of the self-report Barthel Index (SRBI) in people with Parkinsons (PWP) disease. Methods: Thirty-nine PWP completed the SRBI, the self-report Schwab & England (S & E) scale and the PDQ-39. Standard statistical procedures were incorporated to assess the reliability and validity of the SRBI. Results: A Cronbachs alpha coefficient of 0.69 was calculated, indicating adequate internal consistency. Reliability was further demonstrated through a Guttman split-half reliability coefficient of 0.74. Validity was demonstrated through highly significant correlations between the SRBI and the S & E scale (r = 0.64, P < 0.00), the activities of daily living dimension of the PDQ-39 (r = -0.60, P < 0.00) and mobility dimension of the PDQ-39 (r = -0.49, P < 0.01). Conclusions: Results suggest that the SRBI has the potential to be a reliable and valid indicator of ADL in PWP and utilized in studies that make comparisons across conditions. Further validation is required in a larger sample and through assessment of additional psychometric properties.