Functional continuum stratifies fall risk in older adults

Gait speed is a validated indicator of fall risk (Grade 1 A). However, accurate prevention requires comprehensive stratification indicators. The Functional Continuum (FC), which encompasses the full range of functional changes, shows promise for stratifying fall risk. The study included 4,949 and 5,259 individuals from the National Health and Aging Trends Study (NHATS) wave 1 as the discovery sample, and 2,649 and 2,749 newly recruited individuals from wave 5 as the independent validation sample for the gait speed and FC analyses, respectively. At baseline, 19.2% of participants exhibited low gait speed; over follow-up, 66.2% sustained an incident fall. In the FC cohort, baseline distributions for levels 0–3 were 35.0%, 24.9%, 21.0%, and 19.1%, respectively, with 67.7% sustaining an incident fall. Both gait speed and FC function effectively stratified fall risk, with FC showing a significant dose-effect on fall risk. After adjusting for confounders, older adults with low gait speed had an increased fall risk (hazard ratio [HR]: 1.50, 95% confidence interval [CI]: 1.31, 1.71). The worse the FC, the higher the fall risk (Level 1: HR: 1.20, 95% CI: 1.06, 1.36; Level 2: HR: 1.63, 95% CI: 1.43, 1.87; Level 3: HR: 1.80, 95% CI: 1.54, 2.09). FC stratified fall risk into low-, medium-, and high-risk levels, offering a comprehensive, tiered framework for guiding prevention—from general exercise and monitoring in low-risk individuals to intensive measures in higher-risk groups. These findings highlight the potential utility of FC for optimizing resource allocation in fall prevention strategies.