The test-retest reliability and minimal detectable change of the short-form Barthel Index (5 items) and its associations with chronic stroke-specific impairments

[Purpose] To establish the test-retest reliabilities, minimal detectable change of the Short form Barthel Index and associations with stroke-specific impairments. [Subjects and Methods] The Short form-Barthel Index assessment was tested on 24 chronic stroke patients twice, 7 days apart. A relative reliability index (ICC(2,1)), Weighted Kappa Coefficients was used to examine the level of agreement of test-retest reliability for SF-BI, Absolute reliability indices, including the standard error of measurement and the minimal detectable change. The validity was demonstrated by spearman correlation of SF BI-total score with Postural Assessment Scale for Storke, Fugl Meyer Assessment. [Results] There was excellent agreement between test-retest for individual items of BI and total score ICC(2,1)=0.91 and it all showed acceptable SEM and MDC were 2.83 score, 7.84 score respectively. The item-to-total correlations were all significant, ranging from r=0.83–0.92. SF-BI showed good internal consistency. Individual items also possessed high internal consistency 0.82–0.86. The SF-BI and total score were demonstrated high concurrent validity with the PASS, FMA. [Conclusion] This study has demonstrated that the SF-BI is a useful instrument with high test-retest reliability, Absolute reliability indices, internal consistency and validity.