The Clinical Utility of a Six‐Minute Walk Test in Peripheral Arterial Occlusive Disease Patients

Abstract

OBJECTIVES: To determine the test‐retest reliability of the distance covered and the steps taken to complete a 6‐minute walk test by peripheral arterial occlusive disease (PAOD) patients with intermittent claudication. To determine the relationship between the total distance and steps covered during the 6‐minute walk test and clinical measures of PAOD severity. DESIGN: Cross‐sectional design. SETTING: The Claude Pepper Older Americans Independence Center at the University of Maryland at Baltimore. PARTICIPANTS: Sixty‐four PAOD patients between the ages of 45 and 88 years (age = 68 ± 7 years, ankle/brachial index (ABI) = .61 ± .19) were recruited from the Vascular Clinic at the Baltimore Veterans Affairs Medical Center and from radio and newspaper advertisements. MEASUREMENTS: Patients were assessed on a 6‐minute walk test and a treadmill graded exercise test. A second 6‐minute walk test was administered approximately 1 week later. Patients also were characterized in regard to blood pressure in the arms and legs, ABI, anthropometry, body composition, and physical activity. RESULTS: The distances walked during the two 6‐minute walk tests were similar (350 ± 78 m vs 360 ± 73 m), resulting in a high reliability coefficient (R = .94) and a low coefficient of variation (10.4%). The total steps taken during the 6‐minute walk test also were similar (562 ± 113 steps vs 587 ± 107 steps), resulting in a high reliability coefficient (R = .90) and a low coefficient of variation (11.7%). Furthermore, the 6‐minute walking distance correlated with the distances to onset (r = .346, P = .007) and with maximal claudication pain (r = .525, P < .001) during the treadmill test as well as with ABI (r = .552, P < .001). CONCLUSION: The 6‐minute walk test yields highly reliable measurements, which are related to the functional and hemodynamic severity of PAOD, in patients with intermittent claudication.