A scoping review of use of wearable devices to evaluate outcomes in survivors of critical illness

Objective: Wearable devices using new technology may be a cost-effective method to assess functional outcomes in survivors of critical illness. Our primary objective was to review the extent to which wearable devices such as smartphones, pedometers, accelerometers and global positioning systems have been used to evaluate outcomes in survivors of an intensive care unit admission. Design: We included studies of patients surviving an ICU admission and which measured outcomes using wearable devices. We performed a scoping review of studies found by searching the CINAHL, Embase, MEDLINE and PubMed databases. Results: The seven studies we identified were published in or after 2012 and were predominantly descriptive (n = 6) with one randomised controlled trial. All studies described outcomes in cohorts of relatively few participants (range, 11-51 participants). Duration to follow-up was mostly short, at a median time of 3 months after ICU discharge (range, in-hospital to 27 years). All studies used accelerometers to monitor patient movement: physical activity (n = 5), sleep quality (n = 1), and infant movement (n = 1). The accelerometers were bi-axial (n = 3), uni-axial (n.= 2) combined uni-axial (n = 1) and tri-axial (n = 1). Common outcomes evaluated were the number of participants walking for < 30 min/day, mean daily step count and walking speed. Conclusions: Wearable devices have infrequently been used to measure physical activity in survivors of critical illness and all identified studies were published recently, which suggests that the use of wearable devices for research may be increasing. To date, only accelerometry has been reported, and the wide variation in methodologies used and the outcomes measured limits synthesis of these data.