Development of the Brunei Balance Assessment: a new measure of balance disability post stroke

Objective: To report the psychometric properties of the Brunel Balance Assessment (BBA), a new test of balance disability post stroke. Design: Data from 92 subjects were collected and cohorts used to test hierarchical scaling, reliability and validity. Data from 80 people were used to test the hierarchical scaling using an inter-item correlation for redundancy, coefficient of reproducibility (CR) and scalability (CS) for the hierarchy and Cronbach's alpha coefficient for the internal consistency. Thirty-seven people participated in the reliability testing. Test-retest and inter-tester reliability were tested using the kappa coefficient. The testing was repeated on consecutive days to assess test-retest reliability and was scored simultaneously by two physiotherapists for inter-tester reliability. Fifty-five people participated in validity testing. The BBA was compared with the sitting Motor Assessment Scale (MAS), Berg Balance Test (Berg), Rivermead Mobility Index (RMI) using Spearman's rho. Setting: Physiotherapy stroke services of six UK NHS trusts. Participants: Hemiplegic stroke patients were recruited from physiotherapy services and the BBA used to assess their balance. Results: The order of the items was revised and the original 14-point scale reduced to 12 points in the scale development. The revised scale formed a hierarchical scale. Inter-item correlations were < 0.9, coefficients of reproducibility and scalability were 0.99 and 0.69 respectively and Cronbach's alpha was 0.92. Reliability was high (100% agreement) for both aspects of reliability. Correlations with other balance measures were significant (0.83-0.97, p < 0.01) indicating validity as measure of balance disability. Conclusion: The BBA is a reliable, valid, hierarchical measure of balance disability post stroke that is suitable for use in the clinical setting.