Use of the six-minute walk test poststroke: is there a practice effect?

ABSTRACT

OBJECTIVES: To determine whether a practice effect occurs across 2 trials of the six-minute walk test (6MWT) among community-dwelling people within 1 year poststroke and to identify characteristics distinguishing people who show a practice effect from those who do not. DESIGN: Secondary analysis of scores on 2 trials of the 6MWT administered approximately 30 minutes apart at baseline in a randomized controlled trial. SETTING: General community. PARTICIPANTS: People (N=91) living in the community with a residual walking deficit within the first year of a first or recurrent stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Distance walked on the 6MWT. RESULTS: Mean 6MWT scores +/- SD for trials 1 and 2 were 196+/-119m and 197+/-126m, respectively (n=83). The mean difference in 6MWT performance across trials was 0+/-35m (95% confidence interval [CI], -7 to 8m). The Pearson correlation coefficient between 6MWT distances was .96 (P<.001), and the intraclass correlation coefficient was .98 (95% CI, .97-.99). The Bland-Altman plot showed no clear pattern. Participants whose improvement was equal to or greater than the minimal detectable change of 29m between trials (14%) did not significantly differ from those in the rest of the study sample; however, they tended to be younger (P=.05) and more likely to have a mild or moderate gait deficit (P=.06). CONCLUSIONS: Findings do not support a practice effect across 2 trials of the 6MWT in individuals within 1 year poststroke. Thus, a practice walk does not appear necessary. Further research is recommended to evaluate the influence of young age, acute stroke, and mild-to-moderate gait deficit on practice effects.