Background and Purpose: Currently used balance assessments show a ceiling effect and lack activities essential for community mobility in higher-functioning older adults. The aim of this study was to investigate the reliability and validity of the Community Balance and Mobility (CB&M) Scale in a high-functioning community-dwelling older adult population since the CB&M Scale includes assessment of several challenging tasks and may alleviate the ceiling effects observed in commonly used gait and balance assessments for this cohort.
Methods: A convenience sample of 40 older adults (73.4 ± 6.9 years) participated in this cross-sectional study. Previously standardized balance and mobility assessments measuring similar constructs as the CB&M were used for validation. Outcomes included Timed Up and Go Test, Berg Balance Scale (BBS), Dynamic Gait Index (DGI), Functional Reach Test (FRT), Short Physical Performance Battery (SPPB), 6-Minute Walk Test (6MWT), Activities Specific Balance Confidence scale (ABC), gait speed, and intraindividual gait variability. A falls questionnaire documented the history of falls.
Results: Rater reliability (ICC > 0.95) and internal consistency (α= .97) of the CB&M scale were high. CB&M scores demonstrated strong correlations with DGI, BBS, SPPB, and 6MWT (ρ= 0.70-0.87; P < .01); moderate correlations with falls history, TUG, ABC, and gait speed (ρ= 0.44-0.65; P < .01); and low correlations with FRT, swing and stance time variability (ρ= 0.34-0.37; P < .05). Dynamic Gait Index, BBS, SPPB, and ABC assessments demonstrated ceiling effects (7.5%-32.5%), while no floor or ceiling effects were noted on the CB&M. Logistic regression model showed that the CB&M scores significantly predicted falls history (χ2 = 6.66, odds ratio = 0.92; P < .01). Area under the curve for the CB&M scale was 0.80 (95% CI: 0.65-0.95). A score of CB&M ≤ 39 was the optimal trade-off between sensitivity and specificity (sensitivity = 79%, specificity = 76%) and a score of CB&M ≤ 45 maximized sensitivity (sensitivity = 93%, specificity = 60%) to discriminate persons with 2 or more falls from those with fewer than 2 falls in the past year.
Discussion and Conclusions: CB&M scale is reliable and valid to evaluate gait, balance, and mobility in community-dwelling older adults. Unlike some currently used balance and mobility assessments for the community-dwelling older adults, the CB&M scale did not show a ceiling in detection of balance and mobility deficits. In addition, cutoff scores have been proposed that might serve as criteria to discriminate older adults with balance and mobility deficits. The CB&M scale might enable assessment of balance and mobility limitations masked by other assessments and help design interventions to improve community mobility and sustain independence in the higher-functioning community-dwelling older adult.
Department of Clinical and Applied Movement Sciences, Brooks College of Health, University of North Florida, Jacksonville, Florida.
Address correspondence to: Chitralakshmi K. Balasubramanian, PT, PhD, Physical Therapy Program, Department of Clinical and Applied Movement Sciences, Brooks College of Health, 1 UNF Drive, Jacksonville, FL 32225 (firstname.lastname@example.org).
The preliminary data from this study were presented as a poster at the Combined Sections Meeting of the American Physical Therapy Association, January 2013, San Diego, CA, and are accepted for presentation as a poster at the International Society for Gait and Posture Research, June 2013, Akita, Japan.
This study was funded by the Brooks Dean's Professorship Award.
The author declares no conflicts of interest.
Kevin Chui was the Decision Editor.