Time spent lying, sitting, and upright during hospitalization after stroke: a prospective observation study

Early mobilization has been an important part of acute stroke unit treatment. However, early and intense mobilization within the first 24 h post stroke may cause an unfavorable outcome. Recently, objective measurements using body-worn sensors have been applied, enabling continuous monitoring of physical activity in the hospital setting. This study aimed to use body-worn sensors to quantify the amount of physical activity and how activity levels changed over time during hospitalization in patients with acute stroke. We also wanted to investigate which factors were associated with upright and sitting activity.

This was a prospective study including patients admitted to hospital within seven days after onset of stroke. Physical activity was measured by two sensors (ActivPALs from PAL Technologies Ltd., Glasgow, UK), one attached on sternum and one on the thigh of the unaffected side, monitoring continuously from inclusion until discharge. Data were processed in Matlab R 2015B and provided information about daily time in lying, sitting, and upright positions, and daily average duration of sitting and upright bouts. A linear mixed model was used to analyze changes over time.

58 patients were included (31 women, mean (SD) age; 75.1 (12.0)). Patients were hospitalized for 12.1 (7.6) days and had a mean score on the National Institute of Health Stroke Scale of 6.2 (5.5) points. Time spent sitting and time spent upright increased per day during hospitalization by 22.10 min (95% Confidence interval (CI): 14.96, 29.24) and 3.75 min (95% CI: 1.70, 5.80) respectively. Increased time upright was associated with improved Modified Rankin Scale scores (- 38.09 min, 95% CI: -61.88, - 14.29) and higher Short Physical Performance Battery scores (6.97 min, 95% CI: 1.99, 11.95), while prolonged bouts of sitting were associated with more severe stroke (4.50 min, 95% CI: 0.80, 8.19), and older age (1.72 min, 95% CI: 0.20, 3.26).

Patients increased their daily time spent sitting and upright during the initial hospital stay after stroke. Prolonged bouts of sitting were associated with older age and more severe strokes. Hence future research should investigate the benefit of interventions aimed at breaking up sitting time after stroke.