A Comprehensive Sociomedical Framework for Measuring Changes in Physical Functional Status among Older Age Groups

Shuanglin You, University of North Carolina at Chapel Hill
S.L. Bernard, Research Triangle Institute
R.G. Rozier, University of North Carolina at Chapel Hill
Jianwen Cai, University of North Carolina at Chapel Hill

Improvements in the public health of the elderly are most closely tied to understanding functional status trajectories. We developed a framework to disentangle the socio-biomedical aspects of functional status as the fundamental component in the disablement process. Synthesizing existing constructs and principles in the light of Newtonian law of universal gravitation, we extracted five factors from 21 physical functional status indicators, Medicare Current Beneficiary Survey 1991-93. The invariant factor structure over waves has good validity and reliability, loadings and Chronbach Alpha (.80s and .70s), RMA (.02), GFI (.94), and RMSEA (.58 with CI .57-.60). Stability emerged as a self-contained factor adding marginally to factors of lower- and upper-body functioning and transferring-1 and -2. The factors were re-interpreted as a rigorous sequence of physical necessity in human adaptation to his/her own body and the environment. Our unifying theme of physical property corroborated the frameworks of frailty, morbidity and modern physical therapy.