The impact of frailty, activity levels and mitochondrial efficiency on post operative outcomes in older patients undergoing abdominal surgery

Interventions: This will be an observational study of older patients undergoing elective colorectal surgery.
Patients will be recruited at least two weeks and not more than six months prior to surgery.
Markers of frailty will be assessed preoperatively using three different measures.
1. An edmonton frailty scale score (EFS) will be recorded two weeks prior to scheduled surgery
2. Activity levels (using a step counter) will be measured for 10- 14 days prior to scheduled surgery.
3. A blood test assessing mitochondrial function which has been associated with ageing will be performed at two weeks prior to scheduled surgery.
Other than the assessment of these frailty markers, patients will undergo routine perioperative care.
Post operatively, patients will be followed for 100 days and observed for a number of outcomes (specified further in section 4)
EFS will be repeated on day 30 postoperatively
Mitochondrial function blood test will be repeated on day 2 and day 30 postoperatively
Activity levels will be measured from day 2 postoperatively for 14 - 28 days
Primary outcome(s): Hospital length of stay. This includes time spent in tertiary referral centre (ie site of surgery) and time spent in primary rehabilitation hospital. [Day of discharge from rehabilitation hospital]
Study Design: Purpose: Screening;Duration: Longitudinal;Selection: Defined population;Timing: Prospective