To examine heterogeneity in the impact of increased early rehabilitation intensity and to identify which ischemic stroke patients benefit most. We analysed 39,140 propensity score-matched ischemic stroke patients using Diagnosis Procedure Combination database. Patients who received ≥ 60 min of daily rehabilitation within the 14 hospital days were compared with those who received less, in terms of achieving a modified Rankin Scale (mRS) score of 0, 1, or 2 at 60 days. We employed a causal forest model to estimate individualized treatment effectiveness and assessed for heterogeneity in rehabilitation impact across subgroups. Patients in the highest-benefit quartile showed substantial functional improvement (mean Conditional Average Treatment Effect: +17.1%; 95% CI, 15.3-19.0%), characterized by severe baseline activities of daily living (ADL) impairment, age, fewer comorbidities, higher socioeconomic status, better consciousness, and higher rates of reperfusion therapy. Conversely, patients in the lowest-benefit quartile, typically older with moderate ADL impairment, high comorbidities, low socioeconomic status, and limited reperfusion therapy, showed minimal or negative benefit (-16.5%; 95% CI, -18.1% to -14.9%). Rehabilitation dosing impact varied substantially regarding functional ability, with patients having severe strokes, age, fewer comorbidities, and better baseline consciousness deriving the greatest benefit from increased rehabilitation dosing.
Tani et al. (2025) studied this question.