Test–retest reliability of six‐minute walk tests over a one‐year period in patients with chronic heart failure

Purpose The aims of this study were to determine the test–retest reliability of the duplicated six‐minute walk test (6MWT) in patients with chronic heart failure (HF), and to evaluate its variation over time. Methods Forty‐six patients (9 women) with HF performed duplicated 6MWT every third month for 1 year (5 follow‐ups), for a total of 198 paired tests. The patients completed two 6MWT on the same day with a 45‐min seated rest between tests. Results The mean distance in metres, for the first (6MWT1) versus the second (6MWT2), for each follow‐up, was 408 ± 100 versus 411 ± 96, 449 ± 94 versus 465 ± 94, 464 ± 96 versus 473 ± 100, 462 ± 103 versus 468 ± 104 and 472 ± 105 versus 482 ± 107. On average, a marginally, clinically insignificant longer walked distance, 9 m (2.0%), was seen in the second 6MWT. The standard error of a single determination ( S method ) ranged from 2.4% to 3.9% over the study period, and the intraclass correlation coefficient (ICC) ranged from 0.96 to 0.99 (CI 95% 0.94–0.99). The variation over time of ICC or S method was not statistically significant. Conclusion The 6MWT is highly reliable over time in patients with HF, and one test is, therefore, sufficient in clinical follow‐ups.