The association between low pre-operative step count and adverse post-operative outcomes in older patients undergoing...

Multiple tools exist estimating perioperative risk. With an ageing surgical demographic, frailty is becoming an increasingly important concept in perioperative medicine due to its association with adverse post-operative outcomes. Reduced physical activity is a hallmark of frailty, and we postulate that a low pre-operative step count may be an objective measure of frailty. This study aimed to determine the association between low pre-operative step count and post-operative outcomes in patients undergoing elective colorectal cancer surgery.

A prospective analysis of 85 older patients undergoing major elective colorectal surgery was performed at a tertiary centre between October 2017 and October 2018. Patients aged 65 years and over who met inclusion criteria were provided with an activity tracker to wear for 14 days prior to planned surgery. Their median daily step count was measured and a cut-off of < 2500 steps/day was used to define a reduced step count. Primary outcomes included length of stay and 30-day post-operative complication rate. Multivariable logistic regression analyses were used to analyze the influence of low pre-operative step count and other preoperative variables, on post-operative outcomes including mortality, prolonged hospital admission, and complication rates.

Of 85 patients, 17 (20%) were identified as having a low pre-operative step count. A low pre-operative step count was associated with a significantly increased length of stay (14 vs. 6 days, IRR 2.09, 95% CI 1.55-2.83, p ≤ 0.01) and rate of major post-operative complications (29.4% vs. 8.8%, OR 3.34, 95% CI 1.03-14.3, p = 0.04). It was also associated with significantly increased rates of discharge to care facilities (p < 0.01) and requiring support on discharge (p = 0.03).

Low pre-operative step count (< 2500 steps/day) is predictive of an increased risk of post-operative morbidity in patients undergoing elective colorectal surgery. Accurate preoperative identification may allow for treatment modification and tailored perioperative care. The possibility of using a wearable activity tracker as a simple but powerful pre-habilitation tool is raised as an important avenue for future study.

Australian New Zealand Clinical Trials Registry (ACTRN12618000045213).