Comparison of Physical Performance and Muscle Thickness between Older Women with High and Low Fall Risk: A Bayesian Approach

Objective: The present study aimed to compare performance in different functional tests predicting falls between older adults with low and high fall risk. Methods: Seventy-one community-dwelling older women volunteered for this study. Berg Balance Scale (BBS) was used to stratify the sample as: low and high risk for fall (BBS cutoff = ≥ 50 points). The performance in Time Up and Go Test (TUGT), 5-repetition sit-to-stand test (5xSST), 3-meter walk test (3mWT), 3-meter backward walk test (3mBWT). The elbow flexor and knee extensor muscle thickness was obtained by ultrasound (USD). A linear mixed model analysis was used to determine between-group differences in functional mobility and muscle thickness, and Bayesian analysis was applied to check the probability to replicate the same results (i.e., the magnitude of the evidence). Results: The low fall risk group exhibited significantly better performance only in 3mWT (mean difference = 0.84 s [95% CI: 0.40 to 1.29 seconds]; p = 0.001) and 3mBWT (mean difference = 1.54 seconds [95% CI: 0.21 to 2.85 seconds]; p = 0.024). The Bayes Factor (BF) for performance on the 3mWT and 3mBWT shows that the low fall risk group has a probability of 98.7% (BF10 = 77.3) and 99.7% (BF10 = 368), respectively, to perform better than the high fall risk group. Conclusion: Based on inferential and Bayesian analysis, the performance in 3mWT and 3mBWT was classified as very strong to excellent instruments, respectively, to differentiate older women with high fall risk.