Concurrent validity and reliability of the Community Balance and Mobility scale in young-older adults

With the growing number of young-older adults (baby-boomers), there is an increasing demand for assessment tools specific for this population, which are able to detect subtle balance and mobility deficits. Various balance and mobility tests already exist, but suffer from ceiling effects in higher functioning older adults. A reliable and valid challenging balance and mobility test is critical to determine a young-older adult's balance and mobility performance and to timely initiate preventive interventions. The aim was to evaluate the concurrent validity, inter- and intrarater reliability, internal consistency, and ceiling effects of a challenging balance and mobility scale, the Community Balance and Mobility Scale (CBM), in young-older adults aged 60 to 70 years.

Fifty-one participants aged 66.4 ± 2.7 years (range, 60-70 years) were assessed with the CBM. The Fullerton Advanced Balance scale (FAB), 3-Meter Tandem Walk (3MTW), 8-level balance scale, Timed-Up-and-Go (TUG), and 7-m habitual gait speed were used to estimate concurrent validity, examined by Spearman correlation coefficient (ρ). Inter- and intrarater reliability were calculated as Intra-class-correlations (ICC), and internal consistency by Cronbach alpha and item-total correlations (ρ). Ceiling effects were determined by obtaining the percentage of participants reaching the highest possible score.

The CBM significantly correlated with the FAB (ρ = 0.75; p < .001), 3MTW errors (ρ = - 0.61; p < .001), 3MTW time (ρ = - 0.35; p = .05), the 8-level balance scale (ρ = 0.35; p < .05), the TUG (ρ = - 0.42; p < .01), and 7-m habitual gait speed (ρ = 0.46, p < .001). Inter- (ICC_2,k = 0.97), intrarater reliability (ICC_3,k = 1.00) were excellent, and internal consistency (α = 0.88; ρ = 0.28-0.81) was good to satisfactory. The CBM did not show ceiling effects in contrast to other scales.

Concurrent validity of the CBM was good when compared to the FAB and moderate to good when compared to other measures of balance and mobility. Based on this study, the CBM can be recommended to measure balance and mobility performance in the specific population of young-older adults.

Trial number: ISRCTN37750605 . (Registered on 21/04/2016).