Sedentary behavior in the first year after stroke: a longitudinal cohort study with objective measures

Abstract

Objective: To quantify longitudinal changes in sedentary behavior (ie, nonexercise seated or lying behavior) after stroke to ascertain whether reducing sedentary behavior might be a new therapeutic target.

Design: Longitudinal cohort study of patients with acute stroke who were followed over 1 year.

Setting: Acute teaching hospital or outpatient clinic, and the community after discharge.

Participants: A convenience sample of patients with acute stroke (N=96; median age, 72y, interquartile range [IQR]=64-80y; 67% men; median National Institute of Health Stroke Scale score=2, IQR=1-3) who were assessed at 1, 6, and 12 months after stroke.

Interventions: Not applicable.

Main outcome measures: Objective measures of amount and pattern of time spent in sedentary behavior: total sedentary time, weighted median sedentary bout length, and fragmentation index.

Results: Stroke survivors were highly sedentary, spending on average 81% of the time per day in sedentary behavior: median=19.9 hours (IQR=18.4-22.1h), 19.1 hours (17.8-20.8h), and 19.3 hours (17.3-20.9h) at 1, 6, and 12 months, respectively. Longitudinal changes in sedentary behavior were estimated using linear mixed effects models. Covariates were age, sex, stroke severity (National Institute of Health Stroke Scale score), physical capacity (6-minute walk distance), and functional independence (Nottingham Extended Activities of Daily Living Questionnaire score). Higher stroke severity and less functional independence were associated cross-sectionally with more sedentary behavior (β=.11, SE=.05, P=.020 and β=-.11, SE=.01, P<.001, respectively). Importantly, the pattern of sedentary behavior did not change over the first year after stroke and was independent of functional ability.

Conclusions: Stroke survivors were highly sedentary and remained so a year after stroke independently of their functional ability. Developing interventions to reduce sedentary behavior might be a potential new therapeutic target in stroke rehabilitation.

Keywords: Accelerometry; Ambulatory monitoring; Physical activity; Rehabilitation; Sedentary lifestyle; Stroke.