Minimum Detectable Change and Minimal Clinically Important Difference for the Box and Block Test and Fugl-Meyer Assessment in Moderate to Severe Chronic Stroke.

Objectives: To quantify the Minimum Detectable Change (MDC) and the Minimal Clinically Important Difference (MCID) of the Box and Blocks Test (BBT) and Upper Extremity Fugl-Meyer Assessment (FMA-UE), and to determine whether there is a BBT floor effect for individuals with chronic stroke and moderate to severe motor impairment. Design: Analysis of pre- and postinterventional data using anchor and distribution-based methods. Setting: Research laboratory. Participants: Fifty-three adults (N=53) with chronic stroke. Age (mean ± SD)=58.5±10.7; 71% men; mean time poststroke=7.4±6.8 years; baseline FMA=20.6±7.6. Interventions: Randomized controlled trial, including 24 sessions over 8 weeks. Each session included 40 trials of reach-grasp-retrieve-release practice using the ReIn-Hand, with or without robotic support of the arm weight. Main Outcome Measures: A BBT floor effect emerged among participants with baseline FMA-UE (FMA Conclusions: Because of its floor effect, the BBT may not be appropriate for those with severe motor impairment poststroke. MDC values for both BBT and FMA-UE depend on motor impairment severity and should be interpreted using regression model-based estimates. In valid ranges of BBT and FMA-UE, subjective perceived change (Global Rating of Change) showed limited association with them. Distribution-based MCID values were small but meaningful, though they may not reflect participants' perceived importance.