Assessing Clinically Important Differences During Rehabilitation for Stroke: A Pilot Study Evaluating Anchor and Distribution Derived Estimates of Physical Function Change in Classically Summed and Rasch Models of Section GG of the Inpatient Rehabilitation Facility Patient Assessment Instrument.

Cut-off scores obtained using the mRS anchor aligned with more robust estimates of change, as estimated by distribution-based measures. While patients achieving anchor-derived cut-offs have a high probability of mRS improvement, change scores may fail to detect clinically meaningful improvements at these same thresholds. Alternative criteria for determining MCID/CIDs, should be explored. Rasch models require further validation.