Examination of the six minute walk test to determine functional capacity in people with chronic heart failure: a systematic review.

PURPOSE: To evaluate the reliability and validity of the six-minute walk test (6MWT) with respect to its ability to predict functional capacity in patients with chronic heart failure.

METHODS: A systematic review was performed via 8 databases to assess relevant English language full-text articles published from January 1, 1980 to October 31, 2009. Participant characteristics, interventions, reliability, validity, and predictive value for each article with respect to functional capacity as defined by peak VO(2) levels were extracted and compared. Quality Assessment of Diagnostic Accuracy Studies (QUADAS) scores were determined for each study.

RESULTS: Fourteen studies met the selection criteria. Comparison of the studies investigating reliability shows that the 6MWT has good reproducibility. The 6MWT demonstrates moderate correlation with peak VO(2) levels, and ability to predict VO(2) (functional capacity) dependent on distance walked. Cut-off distances vary from 300 to 490 meters depending on the study; if total distance walked remains equal or less than these values, the 6MWT retains its strong predictive value.

CONCLUSION: The 6MWT has good reliability, moderate validity, and a significant ability to predict functional capacity in patients with CHF who do not walk greater than 490 meters.