Validity and responsiveness of the 6 minute walk test for people with fibromyalgia.

Abstract

To determine the concurrent validity and responsiveness of the 6 minute walk test (6-MWT) as a measure of cardiorespiratory fitness in people with fibromyalgia. Subjects completed the 6-MWT, a Fibromyalgia Impact Questionnaire (FIQ), and a peak oxygen consumption (pVO2) exercise test before (n = 28) and after (n = 20) a 12 week exercise program. The correlations between 6-MWT distance and pVO2 before (r = 0.328) and after (r = 0.420) the exercise program were not significant. Significant correlations were obtained between 6-MWT distance and FIQ total (r = -0.494, p < 0.01) and physical impairment (r = -0.403, p < 0.05) scores. Fifteen of 28 subjects completed the exercise program, with significant (p < 0.05) changes in 6-MWT distance (+78 m), pVO2 (+1.8 ml/kg/min), and FIQ total score (-9.9). The change in 6-MWT distance was correlated significantly (p < 0.05) with change in FIQ total score but no change in pVO2. The 6-MWT was not a valid predictor of cardiorespiratory fitness. However, it was sensitive to change and was also significantly related to FIQ total score.