The effects of rehabilitation therapy duration on functional recovery of patients with subacute stroke stratified by individual’s age: a retrospective multicenter study

BACKGROUND: The duration of rehabilitation therapy is one of the key elements for promoting post-stroke functional recovery. However, whether an individual’s age affects the effectiveness of the duration of rehabilitation therapy on post-stroke functional recovery remains unclear. AIM: This study aimed to investigate whether age has an influence on the relationship between the duration of rehabilitation therapy and post-stroke functional recovery. DESIGN: This is a retrospective observational study. SETTING: Six convalescent inpatient rehabilitation hospitals in Japan. POPULATION: The population of the study was represented by a total of 1186 participants with subacute stroke. METHODS: Participants were stratified into four groups according to their age (≤59, 60-69, 70-79, and ≥80 years). The data of minutes involved in performing rehabilitation therapy for participants during hospitalization per day (extracted from the medical records of each hospital). The outcome measurement was the absolute change in the functional independence measure (FIM) score during hospitalization. RESULTS: The mean FIM gains in the ≤59 years, 60-69 years, 70-79 years, and the ≥80 years groups were 38.7 (18.8), 32.8 (18.0), 29.7 (16.6), and 25.4 (17.2), respectively. The results of the multivariate regression analyses showed that there was a significant association between the duration of daily rehabilitation therapy and the FIM gain in the 70-79 years and the ≥80 years groups (-70–79 years group: B=1.289, β=0.290, 95% confidence intervals (CIs): 0.718-1.859, P<0.001; the ≥80 years group: B=2.375, β=0.371, 95% CIs: 1.644-3.107, P<0.001), but not in the other groups. CONCLUSIONS: For patients with subacute stroke in rehabilitation hospitals, a higher duration of daily rehabilitation therapy was associated with better functional recovery in the 70-79 years group and ≥80 years groups. Understanding the responsiveness of patients with stroke to rehabilitation therapy by age group helps to better allocate medical resources and develop more effective approaches. CLINICAL REHABILITATION IMPACT: An increased duration of daily rehabilitation therapy may be helpful in older adults with stroke selected for intensive rehabilitation for improvement of basic daily functioning.