Changes in Physical Functioning as Short-Term Predictors of Mortality.

Abstract

Both performance-based and self-reported measures of physical functioning are predictors of mortality. There has been relatively little research examining whether their changes predict mortality. This study examines whether 5-year changes in performance-based and self-reported measures of functioning predict subsequent mortality. Data are from the 2006 wave of the Social Environment and Biomarkers of Aging Study, 2011 wave of the Taiwan Longitudinal Study of Aging, and mortality follow-up through 2015. Gompertz proportional hazard models predict mortality from changes in ability to complete performance-based tests and changes in performance-based and self-reported functioning. Incident inability to complete at least one performance-based test of functioning is associated with twice the risk of subsequent 4-year mortality. Conditional on the baseline measurement, a one standard deviation (SD) decline in grip strength is associated with a 61% increased risk of 4-year mortality; a one-SD decline in walking speed and a one-SD increase in self-reported limitations are both associated with around a 40% increased risk of 4-year mortality. Conditional on the most recent measurement of functioning, prior change is not significantly associated with subsequent mortality. Repeated measures of performance-based and self-reported functioning are valuable in that they provide an updated measurement of functioning.