Darcy Ummels

12 | Chapter 1 count, distance, energy expenditure, and sleep. 57 However, these results cannot be generalised to older adults and people with a chronic disease because such groups often have altered walking patterns—due to impaired ambulatory abilities—as well as lower walking speeds (e.g., shuffling) which are variables used by the algorithm. 58 ‐ 62 Furthermore, the most important source of physical activity for older adults and people with a chronic disease are household activities, gardening, and walking, 19 and low walking speed often accompany these activities. It is known that low walking speed (<0.8m/s) decreases the validity of activity trackers. 63 ‐ 67 Only few studies have examined the validity of activity trackers among older adults and people with a chronic disease. 68 However, the results of these studies cannot be generalized, as they did not consider the activities of daily living (e.g., free ‐ living protocol), did not use a gold standard, or only used non ‐ commercially available activity trackers. 68 Feasibility of activity trackers for older adults and people with a chronic disease in healthcare Another important property concerns the feasibility of activity trackers. Feasibility is a broad term that includes experiences, acceptability, and usefulness. Studies in healthy adults, 45,69 ‐ 73 older adults, 74 ‐ 76, and people with a chronic disease 77,78 showed that, in general, these target populations are open to using consumer ‐ grade activity trackers. However, older adults and people with a chronic disease indicate that their limited technical skills discourage them from using such trackers. Moreover, no studies have investigated the feasibility of activity trackers or analysed how to embed them in daily clinical practice. The possibility of using activity trackers in healthcare is new, and no guidelines or studies are available to support healthcare professionals in selecting and using activity trackers in their daily clinical practice. Aim and outline of this dissertation There is little to no evidence regarding the validity, feasibility, and use of activity trackers in the healthcare of older adults and people with a chronic disease. This may explain why activity trackers have not been implemented in healthcare, despite the fact that they could potentially be of significant value. Therefore, the main aim of this dissertation is to increase the knowledge about the meaningful use of activity trackers in healthcare for (older) adults with chronic diseases and for older adults with or without chronic diseases.