Validity and reliability of the NIH Toolbox® Standing Balance Test As compared to the Biodex Balance System SD

Abstract

Background/ purpose: The NIH Toolbox® was developed to assess functions among motor, sensory, emotional, and cognitive domains. The motor domain of the NIH Toolbox® includes an assessment for standing balance. Studies have validated early versions of the balance assessment for ages 3 through 85; however, no studies have examined the reliability and validity in its current version (using iPod Touch) against established balance measurements such as the Biodex SD modified clinical test of sensory integration of balance (m-CTSIB).

Subjects: Ninety-three community dwelling older adults (38 males 55 females) ≥60 years old (SD 74 ± 6).

Methods: One-day assessment using the NIH Toolbox® and the Biodex SD m-CTSIB. Intraclass correlation coefficients (ICC_3,1) were used to measure the test-retest reliability, and Pearson's product correlation examined criterion validity.

Results: The overall composite of the Biodex SD m-CTSIB and NIH Toolbox® showed moderate test-retest reliability (ICC_3,1 = 0.71, MDC = 1.21) (ICC_3,1 = 0.84, MDC = 0.65,) respectively. The NIH Toolbox® Theta Score and Biodex overall Sway Index (SI) shows acceptable reliability criterion validity (r = 0.52) indicating moderate overlap in constructs.

Conclusions: The NIH Toolbox®balance assessment demonstrates acceptable criterion validity compared to the Biodex SD m-CTSIB. The NIH Toolbox® is a valid, reliable, and accessible device; therefore, the NIH Toolbox® should be considered for use in clinical evaluations.

Keywords: Biodex Balance System SD; Postural balance; accelerometer; community dwelling older adults; sway.