Accelerometer-Captured Physical Activity Intensity and Functional Recovery Trajectories Following Major Abdominal and Pelvic Cancer Surgery (Preprint)

BACKGROUND Postoperative recovery following major abdominal and pelvic cancer surgery is characterized by substantial declines in physical activity and functional capacity. Wearable accelerometers offer a novel method to objectively quantify recovery trajectories; however, data on activity intensity–specific recovery patterns and the impact of perioperative telemonitoring remain limited. OBJECTIVE To evaluate accelerometer-captured physical activity intensity and postoperative functional recovery trajectories, and to assess whether remote perioperative telemonitoring influences recovery following major oncologic surgery. METHODS This secondary analysis of a randomized comparative effectiveness trial included adult patients undergoing gastrointestinal, genitourinary, or gynecologic cancer surgery. Participants were randomized to remote perioperative telemonitoring or standard surgeon-directed care. Wrist-worn accelerometers measured light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) from baseline through 14 days post-discharge. Patients in the remote perioperative telemonitoring arm with ≤1500 steps per day triggered an alert to nurses who initiated triage encounters. Recovery was defined as percent return to baseline activity using 5-day moving averages. Linear mixed-effects models assessed recovery trajectories over time, adjusting for demographic and surgical factors. Sensitivity analyses were performed using multiple imputation for missing accelerometer data. RESULTS Among 229 evaluable participants, patients recovered 92.7% of baseline LPA and 33.4% of baseline MVPA in the early postoperative period. Daily recovery increased by 0.5% for LPA and 2.2% for MVPA. Minimally invasive surgery was associated with significantly faster recovery for both LPA (+15.6%) and MVPA (+13.7%). Telemonitoring was not associated with statistically significant differences in overall recovery compared to standard care, although recovery rates were modestly faster in the intervention group. Sensitivity analyses using imputed data showed no significant differences in recovery by study arm or surgical approach. CONCLUSIONS Postoperative recovery differs substantially by activity intensity, with rapid return of light activity but persistent deficits in moderate-to-vigorous activity. Minimally invasive surgical approaches are associated with improved recovery trajectories. While perioperative telemonitoring is feasible and well tolerated, its impact on accelerating functional recovery may be limited without targeted behavioral interventions. These findings highlight the importance of intensity-specific activity monitoring and may inform future strategies to optimize postoperative recovery in surgical oncology.