Table 1.

Core Components of Frailty Implicit in the Frailty Literature

Component	Description
State of vulnerability	Acute or chronic stressors elicit a maladaptive response disproportionate to the degree of insult.
Multifactorial etiology	Complex biological processes interact through network effects involving multisystem dysregulation and the age-associated accumulation of molecular, cellular, and tissue damage.
Heterogeneous presentation	Multiple points of entry and dynamic, nonlinear disease progression produce variability in observed characteristics in those affected.
Clinically measurable	Operationalized measurement tools are able to provide a diagnosis of frailty, although a gold standard is notably absent.
Increased risk of adverse outcomes	Patients are subject to increased rates of adverse outcomes including functional decline, decreased quality of life, increased health care utilization, and mortality.

There are 5 general elements central to the definition of frailty that are common throughout the scientific literature examining the condition as a medical syndrome. These elements recognize the presumed underlying biological underpinnings of the development of frailty, along with the clinically relevant implications of the syndrome.