Validation of the six-minute walking test as a measure of postoperative recovery after pancreatic surgery

The six-minute walking test (6MWT) is a measure of functional capacity, but there is limited evidence supporting its use as a postoperative recovery outcome. This study aims to contribute evidence for the validity of 6MWT as a measure of recovery after pancreatic surgery. Following the COSMIN checklist, we analyzed data from patients enrolled in a prospective cohort study at San Raffaele Hospital (2020-2022). Construct validity was tested by hypothesizing that the distance walked in 6 min (6MWD) at 30 days after surgery would be greater in patients known to recover better: (1) younger vs. older, (2) with higher physical status vs. lower, (3) undergoing distal vs. proximal pancreatectomy, (4) laparoscopic vs. open resection, (5) with a shorter vs. longer length of stay, and (6) without severe complications vs. with. Additionally, 6MWD with patient-reported outcomes, including Duke Activity Status Index (DASI) and PROMIS-29 Physical Health Summary Score (PHS), were assessed. Patients (n=151) who completed the 6MWT preoperatively and at 30 days after surgery were analyzed. Data supported construct validity of the 6MWT, showing significantly higher 6MWD in 5 of 6 (83%) groups known to recover better. Only the hypothesis that 6MWT would be higher in younger patients was not confirmed. The 6MWT also showed a moderate positive correlation with DASI (r = 0.41) and PHS (r = 0.47). This is the first study to contribute evidence for the validity of the 6MWT as a measure of recovery after pancreatic resection. Results support the use of the 6MWT as an outcome measure in studies evaluating interventions aimed at improving recovery after pancreatectomy.