Measurement Properties and Minimal Detectable Change of the 6‐Min Step Test for Estimating Cardiorespiratory Fitness in Hospitalized Individuals After Stroke

Abstract

Background: The 6‐minuteute step test is an alternative for estimating cardiorespiratory fitness after stroke.

Objective: To investigate its measurement properties and minimal detectable change early after stroke.

Methods: Cross‐sectional, methodological study. Participants were inpatient individuals in the acute/subacute phase after stroke, who performed the 6‐min step and the 6‐min walk tests. The outcomes of interest were test–retest and inter‐rater reliabilities, validity, measurement error, and minimal detectable change.

Results: Fifty‐one individuals (34 men) with a mean time of 6 days (SD 2) since stroke, and a mean walking speed of 0.9 m/s (SD 0.2) were included. The 6‐min step test had a very‐high test‐retest (ICC 0.93; 95% CI 0.88–0.96) and inter‐rater reliability (ICC 0.95; 95% CI 0.91–0.97). The correlation between the 6‐min‐step test and the 6‐min walk was moderate (r = 0.5; 95% CI 0.3–0.7). The measurement error was 8 (10%) and the minimal detectable change was 21 repetitions.

Conclusion: The 6‐min step test demonstrated appropriate test‐retest and inter‐rater reliability. Agreement with the 6‐min walk test was imprecise, which may reflect the greater physical demand of the 6‐min‐step test. Further studies are needed to examine the relationship between the 6‐min‐step test and maximal cardiorespiratory capacity.