Predicting Activities of Daily Living (ADL) Outcomes in Recovery-Phase Stroke Patients Using the Trunk Impairment Scale: A Validation Study

Trunk function is a key determinant of activities of daily living (ADL) after stroke. While the Trunk Impairment Scale (TIS) has been linked to functional outcomes, its prognostic utility in the recovery phase is less established. This study aimed to develop and validate an ADL prediction model at discharge using the TIS in recovery-phase stroke patients. This prospective cohort study included 80 first-ever stroke patients admitted to Kiminomori Rehabilitation Hospital in Chiba, Japan. Trunk function (TIS), motor function (Stroke Impairment Assessment Set (SIAS)-M), stroke severity (NIH Stroke Scale/Score (NIHSS)), and ADL ( Functional Independence Measure (FIM)-M) were assessed. Three regression models were compared, and predictive validity was tested using cross-validation and bootstrap analysis. The TIS model showed the highest predictive accuracy, outperforming baseline and motor function models. Bootstrap analysis confirmed the independent contribution of one-month TIS to discharge ADL outcomes. The TIS assessed one month after stroke is a reliable predictor of discharge ADL, supporting its use for individualized rehabilitation planning.