Triangulating Clinically Meaningful Change in the Six-minute Walk Test in Individuals with Chronic Heart Failure: A...

Area of Science:

• Cardiology
• Rehabilitation Medicine
• Clinical Measurement

Background:

• The six-minute walk test (6MWT) is a common functional assessment in chronic heart failure (CHF).
• Determining a clinically meaningful change in 6MWT distance (Δ6MWT) is crucial for evaluating interventions in CHF patients.
• Existing data requires synthesis to establish a reliable threshold for meaningful improvement.

Purpose of the Study:

• To estimate the Δ6MWT that signifies a clinically meaningful improvement in individuals with CHF.
• To differentiate between measurement error and true change in 6MWT distance for CHF patients.

Main Methods:

• Systematic literature searches of CINAHL and MEDLINE databases were conducted.
• Included studies reported the intraclass correlation coefficient (ICC) of the 6MWT or used 6MWT as an endpoint in randomized controlled trials (RCTs) of exercise interventions for CHF.
• Minimum detectable difference (MDD) was calculated from ICCs, and receiver operating characteristic (ROC) curves analyzed Δ6MWT against effect sizes for aerobic capacity and health-related quality of life (HRQL).

Main Results:

• The mean MDD for 6MWT was 43.1(16.8) m, indicating the threshold for measurement error.
• A Δ6MWT of 40-45 m was associated with moderate effect sizes in aerobic capacity and HRQL in intervention groups.
• ROC curve analysis suggested thresholds of 19m, 32m, and 48m with varying sensitivity and specificity for discriminating between intervention and control groups.

Conclusions:

• A Δ6MWT of approximately 45 meters surpasses measurement error in CHF patients.
• This 45m threshold is associated with significant improvements in aerobic capacity and/or HRQL.
• This finding provides a valuable benchmark for interpreting 6MWT results in clinical trials and practice for CHF.