An observational study investigating the use of patient-owned technology to quantify physical activity in survivors of critical illness

• Published in: Australian critical care Vol. 33; no. 2; pp. 137 - 143
• Main Authors: Gluck, Samuel, Summers, Matthew James, Finnis, Mark Edward, Andrawos, Alice, Goddard, Thomas Paul, Hodgson, Carol Lynette, Iwashyna, Theodore John, Deane, Adam Michael
• Format: Journal Article
• Language: English
• Published: Australia Elsevier Ltd 01.03.2020
• Subjects: Accelerometer; Adult; Aged; Critical Illness - rehabilitation; Data Collection; Exercise; Female; Humans; Intensive Care Units; Male; Middle Aged; Nursing; Patient Outcome Assessment; Pedometer; Smartphone; Smartphone - instrumentation; Step count; Survivors; Technology; Patient outcome assessment; Accelerometer; Pedometer; Smartphone; Step count
• ISSN: 1036-7314; 1878-1721
• DOI: 10.1016/j.aucc.2019.01.009

Physical activity after intensive care unit (ICU) discharge is challenging to measure but could inform research and practice. A patient's smartphone may provide a novel method to quantify physical activity. We aimed to evaluate the feasibility and accuracy of using smartphone step counts among survivors of critical illness. We performed a prospective observational cohort study in 50 patients who had an ICU length of stay>48 h, owned a smartphone, were ambulatory before admission, and were likely to attend follow-up at 3 and 6 months after discharge. At follow-up, daily step counts were extracted from participants’ smartphones and two FitBit pedometers, and exercise capacity (6-min walk test) and quality of life (European Quality of Life-5 Dimensions) were measured. Thirty-nine (78%) patients returned at 3 months and 33 (66%) at 6 months, the median [interquartile range] smartphone step counts being 3372 [1688–5899] and 2716 [1717–5994], respectively. There was a strong linear relationship, with smartphone approximating 0.71 (0.58, 0.84) of FitBit step counts, P < 0.0001, R-squared = 0.87. There were weak relationships between step counts and the 6-min walk test distance. Although smartphone ownership and data acquisition limit the viability of using extracted smartphone steps at this time, mean daily step counts recorded using a smartphone may act as a surrogate for a dedicated pedometer; however, the relationship between step counts and other measures of physical recovery remains unclear.