Postoperative Complications and Mobilization following Major Abdominal Surgery with vs. Without Fitness Tracker-based Feedback (EXPELLIARMUS)

Abstract

Objective: To determine whether daily postoperative step goals and feedback via a fitness tracker (FT) reduce the rate of postoperative complications after surgery. Background Data: Early and enhanced postoperative mobilization has been advocated to reduce postoperative complications, but it is unknown whether FT alone can reduce morbidity. Methods: EXPELLIARMUS was performed at 11 University Hospitals across Germany by the student-led clinical trial network SIGMA. Patients undergoing major abdominal surgery were enrolled, equipped with a FT and randomly assigned to the experimental (visible screen) or control intervention (blackened screen). The experimental group received daily step goals and feedback via the FT. The primary endpoint was postoperative morbidity within 30 days using the Comprehensive Complication Index (CCI). All trial visits were performed by medical students in hospital with the opportunity to consult a surgeon-facilitator who also obtained the informed consent. After discharge medical students performed the 30-day postoperative visit via telephone and electronic questionnaires. Results: A total of 347 patients were enrolled. Baseline characteristics were comparable between the two groups. The mean age of patients was 58 years and 71% underwent surgery for malignant disease with the most frequent indications being pancreatic, colorectal and hepatobiliary malignancies. Roughly, one third of patients underwent laparoscopic surgery. No imputation for the primary endpoint was necessary as data completeness was 100%. There was no significant difference in the CCI between the two groups in the intention to treat analysis (mean±SD CCI experimental group: 23±24 vs. control: 22±22; 95% CI −6.1, 3.7; P=0.628). All secondary outcomes, including quality of recovery, 6-minutes walking test, length of hospital stay and step count until postoperative day 7 were comparable between the two groups. Conclusions: Daily step goals combined with FT-based feedback had no effect on postoperative morbidity. The EXPELLIARMUS shows that medical students can successfully conduct randomized controlled trials in surgery.