Determining minimally clinically important differences for outcome measures in patients with chronic motor deficits secondary to traumatic brain injury

Objective To determine minimally clinically important differences (MCIDs) for Disability Rating Scale (DRS), Fugl-Meyer Upper Extremity Subscale (FM-UE), Fugl-Meyer Lower Extremity Subscale (FM-LE), and Fugl-Meyer Motor Scale (FMMS) in patients with chronic motor deficits secondary to traumatic brain injury (TBI). Methods Retrospective analysis from the 1-year, double-blind, randomized, surgical sham-controlled, Phase 2 STEMTRA trial (NCT02416492), in which patients with chronic motor deficits secondary to TBI (N = 61) underwent intracerebral stereotactic implantation of modified bone marrow-derived mesenchymal stromal (SB623) cells. MCIDs for DRS, FM-UE, FM-LE, and FMMS were triangulated with distribution-based, anchor-based, and Delphi panel estimates. Results Triangulated MCIDs were: 1) -1.5 points for the Disability Rating Scale; 2) 6.2 points for the Fugl-Meyer Upper Extremity Subscale; 3) 3.2 points for the Fugl-Meyer Lower Extremity Subscale; and 4) 8.4 points for the Fugl-Meyer Motor Scale. Conclusions For the first time in the setting of patients with chronic motor deficits secondary to TBI, this study reports triangulated MCIDs for: 1) DRS, a measure of global outcome; and 2) Fugl-Meyer Scales, measures of motor impairment. These findings guide the use of DRS and Fugl-Meyer Scales in the assessment of global disability outcome and motor impairment in future TBI clinical trials.