Accelerometer-Measured Hospital Physical Activity and Hospital-Acquired Disability in Older Adults

Abstract

Background: Hospital-acquired disability (HAD) is common and often related to low physical activity while in the hospital.

Objective: To examine whether wearable hospital activity trackers can be used to predict HAD.

Design: A prospective observational study between January 2016 and March 2017.

Setting: An academic medical center.

Participants: Community-dwelling older adults, aged 60 years or older, enrolled within 24 hours of admission to general medicine (n = 46).

Main measures: Primary outcome was HAD, defined as having one or more new activity of daily living deficits, decline of four or greater on the Late-Life Function and Disability Instrument (calculated between baseline and discharge), or discharge to a skilled nursing facility. Hospital activity (mean active time, mean sedentary time, and mean step counts per day) was measured using ankle-mounted accelerometers. The association of the literature-based threshold of 900 steps/day with HAD was also evaluated.

Results: Mean age was 73.2 years (SD = 9.5 years), 48% were male, and 76% were white. Median length of stay was 4 days (interquartile range [IQR] = 2.0-6.0 days); 61% (n = 28) reported being able to walk without assistance of another person or walking aid at baseline. Median daily activity time and step counts were 1.1 h/d (IQR = 0.7-1.7 h/d) and 1455.7 steps/day (IQR = 908.5-2643 steps/day), respectively. Those with HAD (41%; n = 19) had lower activity time (0.8 vs 1.4 h/d; P = .04) and fewer step counts (1186 vs 1808 steps/day; P = .04), but no difference in sedentary time, compared to those without HAD. The 900 steps/day threshold had poor sensitivity (40%) and high specificity (85%) for detecting HAD.

Conclusions: Low hospital physical activity, as measured by wearable accelerometers, is associated with HAD. Clinicians can utilize wearable technology data to refer patients to physical/occupational therapy services or other mobility interventions, like walking programs. J Am Geriatr Soc 68:261-265, 2020.

Keywords: accelerometers; hospital disability; hospital mobility; older adults; physical activity.