Predictive factors and dose–response effect of rehabilitation for upper limb induced recovery after stroke: systematic review with proportional meta-analyses

To date, factors with predictive value for upper limb (UL) recovery after stroke are acknowledged, but little is known on clinical features predicting outcome in response to rehabilitation. The purpose of this review is to investigate whether any factor allows identification of Responders to rehabilitation, and whether clinically important recovery of motor function relies on modalities and dose of intervention received, at different times after stroke. A systematic review with proportional meta-analysis was conducted. Longitudinal single-cohort studies on patients undergoing rehabilitation after stroke were included. Predictive features investigated in the included studies were reported. The primary outcome was the Fugl-Meyer Assessment for Upper Extremity, and effect sizes (ES) of different rehabilitation doses were calculated. Only 6% of the included studies (n = 141) investigated predictive factors. Studies providing more than 30 hours of therapy induced small to large clinical effect (ES from 0.38 to 0.88). Task-oriented approach led to the largest effect, both in the subacute (ES = 0.88) and chronic (ES = 0.71) phases. Augmenting interventions provided higher effect in the chronic rather than subacute phase. Integrity of the corticospinal tract, preservation of arm motor function and specific genetic biomarkers were found to be associated with motor recovery Trials on motor recovery after stroke should incorporate analysis of factors associated with rehabilitation outcomes. Task-oriented interventions should be delivered more than 30 hours (high dose) to induce the greatest improvement. Systematic Review Registration Number PROSPERO CRD42021258188. •Demographic characteristics of patients are not associated with rehabilitation-induced upper limb motor outcomes after stroke.•Brain lesion characteristics and residual motor function were found to be the main potential predictive factors of rehabilitation-induced upper limb recovery after stroke.•Task-oriented interventions had the most significant clinical effect, both in the subacute and chronic phases after stroke.•Augmenting interventions are useful in the chronic phase after stroke, if delivered for a minimum of 10 hours.•Priming interventions are more useful in the chronic phase after stroke when 10 to 30 hours of treatment are delivered.