"The dangers of lying in bed": How do sedentary behaviours impact the health of hospitalized patients and how can we reduce them?

Canadian older adults are sedentary for more than 70% of their waking hours. Behaviours such as lying in bed and sitting down to watch TV are now acknowledged as independent health risks even in people who are otherwise active. The risk from prolonged lying/sitting might be even more profound in older adults who become hospitalized. Compared to young people, older adults are more often admitted to hospitals and stay for a longer time. During hospitalization, many spend much of their time lying in bed awake, even when they can walk independently. Hospitalized younger adults experience physiological and cognitive declines, even during short bed rest, and these declines are even greater among older adults. This puts older patients’ post-hospital independence at risk. Despite the adverse outcomes associated with bed rest, no comprehensive assessment of sedentary time is done during hospitalization and there is no standard of care for reducing it. It may be possible to improve hospital outcomes in older patients using light physical activities (e.g. standing, walking). These activities could be beneficial even amongst the sickest and most frail, and may help them maintain their independence. The purpose of this proposed research is to examine whether time spent lying down/sitting affects the health of hospitalized older adults and what physical activity interventions may be helpful in countering these effects. Accelerometers, a state-of-the art device, will be used to monitor the daily sedentary time of older patients during their hospital stay. We expect to determine the minimum sedentary time to reduce the adverse outcomes associated with bed rest during hospitalization. We will also examine the impact of replacing lying down/sitting time with physical activity on health outcomes. For example, we will examine whether substituting 20 minutes/day lying down with 20 minutes/day standing or moving is associated with shorted length of stay during hospitalization