Validating a digital recovery tool for autologous breast reconstruction.

Abstract

Recent research aims to leverage technology to further understand surgical recovery by using continuous data. Traditional metrics of readmission, flap failure, and patient-reported outcome measures are limited by poor accuracy and subjectivity. We aimed to validate smartphone-derived physical activity data to objectively measure and analyze trends in recovery following deep inferior epigastric perforator (DIEP) flap breast reconstruction. A single-center, retrospective study was conducted. Eligible participants who underwent DIEP reconstruction downloaded a bespoke smartphone application, which retrieved data from 1 month preoperatively to 12 months postoperatively. Physical activity was compared and validated against wearable activity monitor data from a previous study. Temporal trends were visualized using mean daily activity values over predefined intervals. Univariable linear regression assessed associations between clinical variables and short-term recovery. Forty-one patients were included in the study. Wearable activity monitor and smartphone datasets (n=10) showed a positive correlation (0.6379, p=0.0105) demonstrating concurrent validity. Analysis of recovery in DIEP patients (n=34) demonstrated a median return to baseline activity at 27 days (IQR 12 days). Physical activity decreased after DIEP, with mean daily activity dropping to 18% of baseline in the first 2 weeks (SD=11%, p<0.0001) before improving to 107% at 8-12 weeks (SD=78%, p=0.9999). Immediate postoperative reconstruction (p=0.046) and lack of postoperative complications (p=0.0063), were short-term predictors of physical activity. This study validates smartphone physical activity as an objective recovery metric in DIEP reconstruction. Future applications include developing recovery prediction models for shared decision-making, implementing perioperative interventions, and postoperative monitoring.