Preclinical Models of Frailty

Frailty refers to the variability in deleterious health outcomes that occur in people of the same age. The two most widely used clinical instruments to quantify the degree of frailty are the frailty phenotype and the frailty index. Both tools have now been reverse-translated for use in aging animals including mice, rats, dogs, and non-human primates. This chapter describes these preclinical frailty phenotype and frailty index tools and explains how they can be used to quantify frailty in animal models. The advantages and disadvantages of both instruments are discussed. This chapter also describes how these preclinical frailty assessment tools can be used to quantify the effects of interventions that attenuate or exacerbate frailty in aging. The use of these animal models of frailty is a significant innovation that allow researchers to measure effects of interventions on healthspan as well as lifespan.