Figure 1:

Representation of conceptual framework of two major theories on frailty. Phenotypic frailty (A) also referred to as physical or syndromic frailty, is hypothesized to have a specific age-related biological basis that drives the appearance of signs and symptoms (outward pointing arrows). Cumulative deficit frailty (B) is hypothesized to be driven by cumulative, non-specific health, functional, psychological and cognitive deficits (inward pointing arrows). Both concepts of frailty predict vulnerability to adverse outcomes and have led to multiple derivative frailty detection tools.