Self-reported versus performance-based measures of physical function: prognostic value for survival

Abstract

The process linking chronic and acute health conditions to disability has been conceptualized as a progression through four stages: 1)pathology;(2)substantial impairments; (3) functional limitations (restrictions in basic physical or mental performance); and (4) disability (difficulties in various activities of daily life, Verbrugge and Jette 1994).

Measures associated with these stages have provided researchers and health professionals with valuable indicators of the current and future health status of community-dwelling populations of older adults. Population-based surveys frequently include measures of the disablement process, either from self-reports or as interviewed-administered performance tests. Although these two types of measuresoften labeled ―subjective‖ and ―objective‖ respectivelyare statistically correlated, they are thought to capture distinct constructs (Reuben et al. 2004).

Nevertheless, both self-reports and performance tasks have been shown to predict subsequent deterioration in health in diverse settings (Bernard et al. 1997; Cooper et al. 2010; Ferrucci et al. 1991; Gill, Robison, and Tinetti 1998; Guralnik et al. 1995; Guralnik et al. 2000; Reuben, Siu, and Kimpau 1992; Tine tti et al. 1995).