Validating the six-minute walk test as a measure of recovery after elective colon resection surgery

Objective: To provide evidence for construct and longitudinal validity of the six-minute walk test (6MWT) as a measure of postsurgical recovery. Design: Data from a randomized clinical trial. Setting: A major teaching hospital in a Canadian urban city. Participants: Patients (N=63) undergoing elective colon resection. Interventions: Not applicable. Main Outcome Measures: Functional walking capacity was measured using the 6MWT at before surgery and at 3 and 6 weeks after surgery. Results: At 3 weeks, 26 (41 %) patients recovered to baseline or greater on the 6MWT distance, and 37 (59%) were at baseline or better by 6 weeks postdischarge. At all time points, the 6MWT distance correlated with age, the American Society of Anesthesiologists (ASA) score of surgical risk, albumin, the physical function subscale of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and the physical component summary score of the SF-36. Baseline 6MWT distance correlated with postoperative 6MWT recovery, and baseline SF-36 and, ASA were associated with postoperative recovery. Patients with intraoperative complications had a clinically relevant lower 6MWT than those without complications at all time points. Conclusions: This study provides evidence for construct validity and sensitivity to change for the 6MWT as a measure of surgical recovery.