Use of the 6-Minute Walk Test as Gait Therapy for Hemiplegic Patients: Possibility of Practice Effect by Providing Knowledge of Result

ABSTRACT

BACKGROUND: This study aimed to investigate the practice effect of the 6-minute walk test (6MWT) after providing the subjects with knowledge of the results (KR). METHODS: Sixteen subjects with post-stroke hemiparesis volunteered to participate in this study. The 6MWT was performed by having the subjects take repeated walks along a 20-m walkway for 6 minutes; and the maximum distance walked was recorded. Two trials of the 6MWT were conducted under three conditions no-KR, immediate-KR (providing knowledge of the time taken to complete each 20-m distance), and summary-KR (providing knowledge of the time taken to complete 60 m). RESULTS: The practice effects of all 3 conditions were determined by using the paired t-test, intraclass correlation coefficient (ICC) with <0.75, and the Bland-Altman plot. The findings of the paired t-test showed a significant difference under the immediate-KR condition only; however, no significant differences were noted under the no-KR and summary-KR conditions. In a data agreement analysis across the two trials using the ICC, none of the obtained values under the three conditions were in an acceptable range indicative of a practice effect. In the Bland-Altman plot, a greater data variation was observed under the immediate-KR condition than under the other two conditions. When comparing the conditions, the immediate-KR condition differed significantly from the no-KR condition. CONCLUSIONS: Our findings do not support the presence of a practice effect across the 6MWT. However, a practice effect seems to be clinically possible when the immediate-KR condition is incorporated into this test.