Clustering of Sedentary Behavior and Longitudinal Changes in Patients With Stroke Undergoing Rehabilitation

BACKGROUND AND PURPOSE: Sedentary behavior (SB) is highly prevalent during stroke rehabilitation. Evaluating both the duration and pattern of SB may inform tailored interventions. This study aimed to classify patients with stroke undergoing inpatient rehabilitation into distinct subgroups based on multiple SB indicators at admission and examine their longitudinal changes in SB outcomes over a 1-month period. METHODS: This multicenter prospective longitudinal study was conducted across 14 rehabilitation hospitals in Japan. SB was objectively assessed using triaxial accelerometers at admission and at 1 month. K-means clustering was applied to the following 5 SB-related variables: short (<30 minutes), medium (30-59 minutes), and long (≥60 minutes) sedentary bout ratios; total SB time; and break frequency. Longitudinal changes were examined using generalized linear mixed models. RESULTS: A total of 420 participants (median age 71.0 years; 57.9% male) were enrolled. Clustering analysis identified 3 subgroups: low SB (n = 109), moderate SB (n = 196), and high SB (n = 115). Generalized linear mixed models showed significant main effects of time for most SB indicators, except the long SB bout ratio. Significant group × time interactions were observed for the short and medium SB bout ratios and break frequency in the low SB group and for the medium and long SB bout ratios in the high SB group (P < 0.05). DISCUSSION AND CONCLUSIONS: Three distinct SB phenotypes were identified among patients with stroke during inpatient rehabilitation. Early behavioral profiling using SB indicators may support the development of individualized strategies to reduce sedentary time.