All participants will be asked to complete baseline assessments and a blood test.

30 participants out of the 100 will be selected to wear a digital motion device before their surgery for seven days. (15 participants will be non-frail and 15 patients will be frail).

Where possible, all baseline assessments will be scheduled to coincide with a routine clinic/hospital visit. The first assessment will complete functional, frailty, nutritional, and quality of life questionnaires. A blood test will be taken for baseline tests and metabolomic assessment. Participants who opt into having a digital motion device will also be shown how to use the device and will wear this for seven days. Written instructions to fit the device will also be given.

The development of biochemical assessments of frailty could also provide valuable information to guide the treatment of the older patient although there are very few that have been validated for clinical use across a range of settings.

A further potential measure of frailty is tissue levels of senescence. Senescent cells are rare in the tissues of young organisms but become more common as tissues age, especially in adipose tissue, muscle and skin (Tchkonia et al., 2010). Both ageing and frailty are associated with cellular senescence, a mechanism of irreversible cell cycle arrest caused by persistent stress and damage, which contributes to the process of ageing, frailty and a range of diseases (Xu et al., 2018; Hickson et al., 2019). Senescent cells are causal to a wide range of diseases such as arthritis, arteriosclerosis and dementia and are also linked to the development of frailty in animal models.

A simple, validated biomarker of frailty, capable of identification of patients who are at an increased risk of adverse outcomes from surgery, would be of great value in the surgical decision-making process.

as above