Measurement properties of step tests for exercise capacity in COPD: A systematic review.

Only articles in English or Portuguese were included, and conference abstracts were excluded, so some relevant studies may be missing. Initial screening was done by one reviewer, although two reviewers then checked full texts and resolved disagreements. Many included studies were not designed specifically to test measurement properties, which can weaken confidence in the ratings. Reliability and responsiveness were rated very low for most tests because many test-retest studies were done on the same day and responsiveness analyses used only paired t-tests or Wilcoxon tests. Evidence was heterogeneous, and some tests were represented by only isolated articles. The review reports article counts rather than a total participant count, so the size of the evidence behind each rating is not clear.

The authors declared no potential conflicts of interest and received no financial support for the work.

Do not conclude that the six-minute stepper test is a validated replacement for established exercise capacity tests in COPD. The review rated most step test evidence low or very low, and the six-minute stepper test still had very low reliability and measurement error.