Illnesses in the older patient presenting to the ED are more likely to be of a higher acuity compared to younger patients. They are more likely to arrive by ambulance, they are more likely to be acutely unwell even when they appear stable on initial evaluation, and they are more likely to require immediate critical care.

Older patients often present with non-specific problems including the classic ‘geriatric giants’: falls, delirium, immobility and incontinence. These presenting complaints are often representative of multi-factorial disorders including underlying illness and comorbidity that require consideration of a broad differential; the assessment of these older patients requires skilful history and examination.

The presentation of frail patients to the ED and acute medical unit (AMU) is attracting increasing interest. These patients have previously not been a priority and have fallen through gaps in an environment designed to treat condition-specific problems rather than address the more complex issues which can present in a patient who is ‘frail’. Mortality rates of frail older patients presenting to EDs and AMUs is high and as such, this condition must be addressed by emergency physicians and acute physicians.

A large study on frail adults who were discharged from the ED showed they have a poorer 30-day outcome that non-frail patients, with between 10% and 45% (depending on level of frailty) increased risk of hospitalisation, nursing home admission and death (6). Studies such as these make the recognition and diagnosis of frailty early in an acute illness episode imperative so that interventions can be planned and initiated.

A recent international consensus on the definition of physical frailty defines it as, ‘a medical syndrome with multiple causes and contributors that is characterised by diminished strength, endurance, and reduced physiologic function that increases an individual’s vulnerability to increased dependency and/or death’ (7).

The definitive diagnosis of frailty is usually made by a geriatrician and can be based on any number of well-validated models of frailty; two of the most well-known theoretical concepts of frailty are the frailty phenotype (Fried) (Box 1.1) and the frailty index (Rockwood).

In the ED or AMU setting, the frailty phenotype may be more appropriate as it can be applied at first contact; the frailty index is a deficit accumulation model that has many strengths but does require comprehensive medical and functional assessment before it can be applied.