Functional status and older age

Functional status is an important component of clinical assessment when considering older adults for ICU admission, and their ability to survive and recover from an episode of critical illness. In those who survive, many older adults will experience a decline in physical function. Functional status is intrinsically linked to other features associated with ageing, including frailty, disability and comorbidity. For this reason, intensive care clinicians will benefit from an understanding of functional status in the context of normal ageing, and how an individual’s pre-illness function impacts on ICU outcomes.
In this chapter, we will evaluate the interaction between chronological ageing and changes in functional status, as well as risk factors for decline in functional status in the older general population. We will then critically evaluate current instruments used to measure functional status in older people, with a particular focus on assessment in the critical care unit. We conclude the chapter with an analysis of the evidence base relating to pre-morbid functional status and its relationship with outcomes for critically ill older people