Estimating the minimal clinically important difference of upper extremity outcome measures in chronic stroke patients with moderate to severe impairment: a cross-sectional study

Abstract

Background: Approximately 70% of chronic stroke patients experience upper extremity (UE) functional impairments, and UE outcome measures are often used as quality-of-life indicators. Objective: The purpose of this study was to estimate minimal clinically important difference (MCID) values for UE outcome measures in chronic stroke patients with moderate to severe UE hemiplegia. Methods: This study was a cross-sectional study, conducted as a secondary analysis of data from the ReoGo-J study, a multicenter, prospective, randomized, parallel-group trial of robot-assisted self-training for UE hemiplegia in chronic stroke. The patients were randomized to 1 of 3 treatment groups. Treatment was provided 3 times a week for 10 weeks, and UE outcome measures were evaluated before and after treatment. The anchor-based method was used to estimate MCID values for UE outcome measures, with Stroke Impact Scale (SIS) subscales as anchors. MCID values were estimated by identifying cutoff values in a receiver operating characteristic (ROC) curve. Results: Between-group comparisons of UE outcome measures, based on the clinically important difference (CID) values of SIS subscales, revealed significant differences in both the Amount of Use (AOU) and Quality of Movement (QOM) components of the Motor Activity Log (MAL)-14. The estimated MCID values were 0.89 for the AOU component and 0.77 for the QOM component. Conclusions: The estimated MCID values for the MAL-14 not only add information regarding the clinical characteristics of the MAL-14 but also facilitate interpretations of changing scores in chronic stroke patients with moderate to severe UE hemiplegia undergoing rehabilitation therapy. Study registration: https://www.umin.ac.jp/ctr/index.htm (UMIN000022509; 1 July 2016).