Reliability and Validity of a Modified Version of the Community Balance and Mobility Scale (CBMS-Home) for Use in Home Assessment

Objective. The Community Balance and Mobility Scale (CBMS) has been shown to be a valid and reliable outcome measure for evaluating balance and mobility among older adults; however, some items cannot be conducted in all home environments, limiting its use in home-based assessments. The purpose of this study was to evaluate the accuracy and selected measurement properties of a modified 12-item CBMS-Home (8 original items and 4 modified items of the CBMS) feasible for use within the constraints of home assessments for older adults. Methods. Fifty-five people (mean [SD] age=77.2 [6.0] years) were recruited for this validation study. Participants completed the full original CBMS, CBMS-Home (the modified items of the CBMS), the Functional Reach Test, and Step Test. Principal components analysis, internal consistency, test-retest and intermethod reliability, agreements within and between methods, and criterion validity were calculated. Results. Principal components analysis of CBMS and CBMS-Home both revealed 3 similar components and loadings. Bland-Altman and weighted kappa analyses revealed that the CBMS-Home demonstrated moderate to almost perfect agreement (weighted kappa=0.45-0.84) with CBMS. The distribution of scores of CBMS-Home were satisfactory, and other results showed excellent test-retest (intraclass correlation coefficient [ICC] =0.95) and intermethod reliability (ICC =0.94) and internal consistency (Cronbach alpha=0.94). There were no ceiling effects (0%) or floor (1.8%) effects. CBMS-Home demonstrated a low (Spearman rho=0.39) and moderate positive (Spearman rho=0.63) relationship with the Functional Reach Test and Step Test, respectively. Conclusions. The CBMS-Home has good psychometric properties and provides a useful multidimensional assessment tool. Impact. A modified version of the CBMS (CBMS-Home) can be confidently used to assess older adults-within their own home-who might have mild balance impairments.