# The Dubousset functional test: a reliable and validated physical function and balance assessment tool for older Chinese adults

## TL;DR

The Dubousset Functional Test is a reliable tool for assessing physical function and balance in older Chinese adults.

## Contribution

This study validates the Dubousset Functional Test's psychometric properties in the aging Chinese population for the first time.

## Key findings

- The DFT showed high test-retest reliability across all four components.
- Strong correlations were found between DFT components and the 30s-STS in the oldest old-aged group.
- Older adults performed significantly worse than young adults on all DFT components.

## Abstract

The Dubousset Functional Test (DFT) offers a standardized, objective assessment to evaluate physical performance, trunk and lower extremity muscle strength, balance, and motor-cognitive integration. However, the psychometric properties of DFT in the aging Chinese population remain unexamined. Therefore, this study aimed to determine the psychometric properties of the DFT in older Chinese adults.

A cross-sectional psychometric design was employed, using convenience sampling. The DFT involves four components: (1) The Steps Test; (2) The Up and Walking Test; (3) The Down and Sitting Test; (4) The Dual-Tasking Test. To examine test-retest reliability, a subset of 20 participants was randomly selected from the total sample using a random number table and retested in a one-day interval. The 30 s Sit to Stand Test (30s-STS) was selected as the reference test to examine concurrent validity. Healthy control young adult participants were recruited to examine discriminant validity. SPSS version 26.0 and R software (version 4.1.0) were used to perform the data analysis.

Fifty participants were included in this study. Regarding the test–retest reliability, the ICC (95% CI) were 0.914 (0.756, 0.967), 0.985 (0.963, 0.994), 0.970 (0.926, 0.988), 0.964 (0.910, 0.986) for the steps test, the up and walking test, the down and sitting test, and the dual-tasking test, respectively. Moderate negative correlations were observed between the 30s-STS performance and the three components of the DFT: steps test (r = -0.45, P < 0.001), up and walking test (r = -0.52, P < 0.001), and down and sitting test (r = -0.51, P < 0.001). Subgroup analysis by age revealed that significant correlations were exclusively observed in the oldest old-aged group between the three components of the DFT (i.e., the steps test, up-and-walking test, and dual-tasking test) and the 30s-STS. Statistically significant differences were observed between older adults and healthy young adults for all components of DFT (all P < 0.001).

The Dubousset Functional Test demonstrated relatively good psychometric properties for geriatric functional assessment.