Validity and Reliability of the 6-Min Step Test in Individuals with Coronary Artery Disease.

Objective To assess the validity and reliability of the 6-min step test (6MST) in individuals with coronary artery disease (CAD). Methods In a randomized and crossover design, 35 patients with CAD (65.8 +/- 9.6 years), referred by a physician of a cardiology ambulatory, performed two 6MSTs and two 6-min walk tests (6MWTs) in order to assess reliability in patients with arterial coronary disease. The order of performance of the tests was established by a draw. Results 6MST test-retest reliability was excellent (intraclass correlation coefficient = 0.967; 95% CI: 0.766, 0.989; p < .05). There was an increase of 7.9 +/- 8.2 steps from the first to the second 6MST, with a technical error of measurement = 8.0; p < .001. The correlations between distance walked in the 6MWT and number of steps in the 6MST in the first and second tests were 0.6 and 0.7 (p < .001), respectively. Conclusion The 6MST is a reliable test to measure functional capacity in individuals with CAD. The test is valid when using 6MWT as the gold standard. There is an 88% chance of a subject classified in a given tertile by the 6MWT being in the same tertile in the 6MST.