Abstract
Low amounts of physical activity (PA) and prolonged periods of sedentary activity are common in hospitalized patients. Objective PA monitoring is needed to prevent the negative effects of inactivity, but a suitable algorithm is lacking. The aim of this study is to optimize and validate a classification algorithm that discriminates between sedentary, standing, and dynamic activities, and records postural transitions in hospitalized patients under free-living conditions. Optimization and validation in comparison to video analysis were performed in orthopedic and acutely hospitalized elderly patients with an accelerometer worn on the upper leg. Data segmentation window size (WS), amount of PA threshold (PA Th) and sensor orientation threshold (SO Th) were optimized in 25 patients, validation was performed in another 25. Sensitivity, specificity, accuracy, and (absolute) percentage error were used to assess the algorithm’s performance. Optimization resulted in the best performance with parameter settings: WS 4 s, PA Th 4.3 counts per second, SO Th 0.8 g. Validation showed that all activities were classified within acceptable limits (>80% sensitivity, specificity and accuracy, ±10% error), except for the classification of standing activity. As patients need to increase their PA and interrupt sedentary behavior, the algorithm is suitable for classifying PA in hospitalized patients.
Highlights
Low amounts of physical activity (PA) and prolonged periods of uninterrupted sedentary activity are common in hospitalized patients
The results show that with an accelerometer worn on the upper leg, the best classification performance for HFITAL was achieved with the following parameter settings: a data segmentation window size (WS) of 4 s, an amount of physical activity threshold (PA Th), of 4.3 cps, and a sensor orientation threshold (SO Th) of 0.8 g
As hospitalized patients need to increase their amount of PA and break up prolonged periods of sedentary activity, the classification of dynamic activity and the detection of postural transitions are considered the most important outcome measures for PA monitoring [1,35,45]
Summary
Low amounts of physical activity (PA) and prolonged periods of uninterrupted sedentary activity are common in hospitalized patients. Little time is spent being active, and bouts of standing and walking are usually short [6,7]. This sedentary behavior is found in all patient subpopulations. Low amounts of PA and prolonged periods of uninterrupted sedentary activity during hospitalization have been associated with functional decline [29,30], a decline in physical performance [30], increased insulin resistance [30], increased length of stay [31], increased risk of institutionalization [16], and mortality [29,32,33,34]. In order to support (i.e., perform and/or evaluate) such interventions, it is necessary to measure patients’ PA behavior in an objective and accurate way [2,40,41]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
