Motor Outcomes of Robot-Assisted Versus Conventional Occupational Therapy for Upper-Limb Recovery in Subacute Stroke: A Retrospective Cohort Study with Exploratory Neurocognitive Outcomes.

Background/Objectives: Robot-assisted therapy (RAT) can deliver repetitive, feedback-enriched upper-limb practice after stroke, but evidence comparing RAT with dose-matched conventional occupational therapy (COT) under routine inpatient conditions-and concurrent neurocognitive data-remains limited. We compared motor recovery between an end-effector RAT-based program (30 min RAT plus 30 min COT) and dose-matched COT alone in subacute stroke survivors, with neurocognitive outcomes prespecified as exploratory endpoints. Methods: In this single-center retrospective non-randomized cohort study, adults with first-ever ischemic or hemorrhagic stroke who completed routine baseline and week-4 assessments received 4 weeks of upper-limb rehabilitation: combined RAT plus COT (60 min daily) or COT alone (60 min daily). The primary outcome was the week-4 Fugl-Meyer Assessment-Upper Extremity (FMA-UE) motor score adjusted for baseline. Primary inference used covariate-adjusted linear regression on outcome-specific complete cases, with a prespecified stabilized inverse probability of treatment weighting (IPTW) average treatment effect analysis as the sensitivity test. Secondary and exploratory endpoints were interpreted descriptively; Benjamini-Hochberg false discovery rate (FDR) control and multiple imputation were applied as supportive analyses. Results: The analytic cohort comprised 65 patients (RAT, n = 33; COT alone, n = 32). Both groups improved over 4 weeks, but the RAT group had worse baseline upper-limb motor status. The adjusted between-group difference for the week-4 FMA-UE motor score was non-significant (adjusted mean difference, 4.39; 95% confidence interval (CI), -2.43 to 11.21; p = 0.203), and the stabilized IPTW estimate was concordant (β = 2.17; 95% CI, -3.63 to 7.98; p = 0.464). In unadjusted analyses, the FMA-UE motor gain was larger after RAT than COT alone (14.70 ± 15.53 vs. 7.91 ± 9.42), and only the RAT group exceeded the prespecified 12.4-point clinically important threshold; this signal attenuated after adjustment. No secondary or exploratory endpoint remained significant after FDR control. Multiple imputation for the primary endpoint was concordant with the complete-case result (pooled β = 4.52; 95% CI, -1.91 to 10.94; p = 0.168). Conclusions: End-effector RAT did not demonstrate adjusted superiority over dose-matched COT alone for upper-limb motor recovery. The larger unadjusted FMA-UE gain should be interpreted as a descriptive impairment-level signal rather than as evidence of comparative efficacy. Neurocognitive results were exploratory; the retrospective non-randomized design, baseline imbalance, differential missingness, and unavailable confounder data require cautious interpretation.