Changes in Physical Functioning as Short-Term Predictors of Mortality

Abstract

Objectives: 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.

Method: 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.

Results: 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.

Discussion: Repeated measures of performance-based and self-reported functioning are valuable in that they provide an updated measurement of functioning.

Keywords: Death and dying; Functional health status; Longitudinal methods; Measurement.