Using the 6-minute walk test to predict disability-free survival after major surgery

Area of Science:

• Perioperative Medicine
• Functional Assessment
• Surgical Outcomes Research

Background:

• The 6-minute walk test (6MWT) is a widely used functional assessment tool.
• The prognostic value of the 6MWT for disability-free survival (DFS) remains unclear.

Purpose of the Study:

• To evaluate the correlation of preoperative 6MWT distance with recovery outcomes.
• To assess the prognostic utility of the 6MWT for 12-month DFS compared to other risk assessment tools.

Main Methods:

• A sub-study of the Measurement of Exercise Tolerance for Surgery (METS) trial.
• Co-primary outcomes included correlation of 6MWT with 15-item quality of recovery and WHO Disability Assessment Schedule scores.
• Logistic regression and ROC analysis assessed prognostic utility for 12-month DFS.

Main Results:

• The 6MWT showed weak correlations with 30-day quality of recovery and 12-month WHO DAS scores.
• Lower 6MWT tertiles were associated with significantly higher odds of reduced DFS (OR 3.13).
• The Duke Activity Status Index (DASI) was the sole independent predictor of DFS (aOR 1.06), outperforming 6MWT and peak oxygen consumption in ROC analysis.

Conclusions:

• The Duke Activity Status Index (DASI) demonstrates superior predictive value for DFS compared to the 6MWT.
• The 6MWT is a safe functional assessment, comparable to cardiopulmonary exercise testing for predictive purposes.
• Further research is needed to establish optimal 6MWT distance thresholds for risk stratification.