Abstract
BACKGROUND: When older adults fall below the thresholds of functional geriatric assessment (FGA), they may already be at risk of mobility impairment. A reduction in (jumping) power could be an indication of functional decline, one of the main risk factors for falls. OBJECTIVE: This paper explores whether six-month delta (∆) values of muscle power can predict 24-month follow-up FGA in older adults. METHODS: This observational study of independent, healthy, high-performing community-dwelling adults aged 70 + years involved FGA (mobility, balance, and endurance tests) at baseline (t(0)), after 6 months (t(1)), and after 24 months (t(2)); maximum jumping power (max JP) was determined at t(0) and t(1). A predictive linear model was developed in which the percentage change of Δmax JP(0,1) was transferred to all FGA (t(0)) values. The results were compared with measured FGA values at t(2) via sensitivity and specificity in terms of the clinically meaningful change (CMC) or the minimal detectable change (MDC). RESULTS: In 176 individuals (60% female, mean age 75.3 years) the mean percentage (SD) between predicted and measured FGA ranged between 0.4 (51.3) and 18.11 (51.9). Sensitivity to identify the CMC or MDC of predicted FGA tests at t(2) ranged between 17.6% (Timed up and go) and 75.0% (5-times-chair-rise) in a test-to-test comparison and increased to 97.6% considering clinically conspicuousness on global FGA. CONCLUSION: The potential of jumping power to predict single tests of FGA was low regarding sensitivity and specificity of CMC (or MDC). 6 months Δmax JP seem to be suitable for predicting physical function, if the measured and predicted tests were not compared at the test level, but globally, in the target group in the long term.