Figure 1.

The Frailty Concept. In a simple model displaying the clinical trajectory of a frail patient compared with a nonfrail phenotype, a clinical insult such as an illness may worsen each patient’s clinical condition (dotted line with arrowheads). The frail patient, however, requires less clinical insult to rapidly decompensate below the level of intrinsic physiologic reserve and become critically ill (purple line). The nonfrail patient has more time to respond to treatment and has a stronger chance of recovery (green line) when compared with the frailty phenotype.