Mobility measures and waking-day movement behaviour composition among older adults: a compositional data analysis of the McMaster Monitoring My Mobility study.

Abstract

Background: Mobility is a cornerstone of healthy ageing typically assessed using self-report and performance-based measures. Recent research suggests these measures are poor proxies for real-world mobility. Device-derived measures of real-world mobility reflect the relative proportions of time a person allocates to sedentary behaviour (SB), light-intensity physical activity (LIPA), and moderate-to-vigorous physical activity (MVPA) that together form the waking-day movement behaviour composition. The aim of this study was to examine the associations between commonly used mobility measures and the waking-day movement behaviour composition in older adults.

Methods: A cross-sectional analysis of data from over 1200 older adults ≥ 65 years of age from the baseline cohort (2022-2024) of the McMaster Monitoring My Mobility (MacM3) study was conducted. Compositional data analysis was used to examine the associations between 6 self-report and 10 performance-based measures of mobility and multiple components of the waking-day movement behaviour composition and establish differences in movement behaviours according to different levels of mobility. Examples of included measures are the Physical Activity Scale for the Elderly (PASE) and Timed Up and Go (TUG).

Results: Data from 1227 older adults (73.6 ± 5.3 years) were analysed. Significant differences in waking-day movement behaviour composition were found across the self-report and performance-based mobility measures. Older adults with lower mobility accumulated more SB and less MVPA throughout the day. For example, those with poorer TUG performance accumulated 34 more minutes/day of SB, and 22 min/day less of MVPA compared to those with better performance. The PASE, 400-meter walk, and fast gait speed tests were the strongest indicators of real-world mobility; however, the effect sizes were small. No measure showed a significant association with LIPA.

Conclusions: Traditional self-report and performance-based measures of mobility are associated with the waking-day movement behaviour composition in older adults; however, their ability to explain real-world mobility is limited and varies across measures. The lack of association between any of the measures and LIPA is surprising, given that older adults spend most of their time in this activity intensity. These findings challenge the widespread use of traditional mobility measures to make inferences about real-world mobility.