Abstract
PURPOSE: Functional independence measure (FIM) is a detailed assessment of activities of daily living in patients with stroke. To confirm that the FIM is useful in clinical practice and clinical research, the minimal important change (MIC), which is an aspect of interpretability of the FIM, must be clarified in addition to validity and reliability. This study aimed to estimate the MIC of the FIM in older patients with subacute stroke, with the goal of enhancing the interpretability of rehabilitation outcomes in geriatric care. METHODS: Data from patients admitted to a single convalescent rehabilitation ward (CRW) in Japan between January 2020 and December 2022 were analyzed. This study included patients aged 65 years or older with subacute stroke who were originally living at home. Those who died or were transferred to other hospitals during hospitalization were excluded. FIM was assessed on admission and discharge. The MIC for the FIM was calculated using the place of discharge as an anchor (i.e., anchor-based adjusted predictive modeling method [MIC(adj)]). RESULTS: Of the 1401 patients admitted to the CRW, 277 were eligible (mean age [SD], 78.9 [7.6] years). The motor, cognitive, and total FIM scores on CRW admission were 39.1 (21.2), 19.7 (8.5), and 58.8 (27.7) and those at CRW discharge were 60.9 (23.9), 23.9 (8.4), and 84.8 (30.7), respectively. The estimated MIC(adj) for the motor, cognitive, and total FIM scores were 18.6, 3.9, and 22.8, respectively. CONCLUSIONS: The MIC for the FIM in older patients with subacute stroke were 19, 4, and 23 points for the motor, cognitive, and total FIM, respectively, which may aid in interpreting the effects of rehabilitation in older patients with subacute stroke.