The minimal clinically important difference of six-minute walk in Asian older adults

Abstract

Background: Rehabilitation interventions promote functional recovery among frail older adults and little is known about the clinical significance of physical outcome measure changes. The purpose of our study is to examine the minimal clinically important difference (MCID) for the 6-minute walk distance (6MWD) among frail Asian older adults. Methods. Data from the "Evaluation of the Frails' Fall Efficacy by Comparing Treatments" study were analyzed. Distribution-based and anchor-based methods were used to estimate the MCID of the 6MWD. Participants who completed the trial rated their perceived change of overall health on the Global Rating of Change (GROC) scale. The receiver operating characteristic curve (ROC) was used to analyze the sensitivity and specificity of the cut-off values of 6MWD (in meters) for GROC rating of "a little bit better" (+2), based on feedback from participants. Results: The mean (SD) change in 6MWD was 37.3(46.2) m among those who perceived a change (GROC ≥ 2), while those who did not was 9.3(18.2) m post-intervention (P = 0.011). From the anchor-based method, the MCID value for the 6MWD was 17.8 m (sensitivity 56.7% and specificity 83.3%) while distribution-based method estimated 12.9 m. Conclusion: The MCID estimate for 6MWD was 17.8 m in the moderately frail Asian older adults with a fear of falling. The results will aid the clinicians in goal setting for this patient population. Trial registration. Australian New Zealand Clinical Trials Registry number: ACTRN12610000576022. © 2013 Kwok et al; licensee BioMed Central Ltd.