Background
Despite being critical for maintaining function in older adults, physical activity is rarely measured and poorly documented in hospital settings. In order to understand physical activity measurement in hospitals, and ultimately improve consistency of reporting, this scoping review sought to identify physical activity outcomes and measurement tools used within randomised controlled trials (RCTs) of physical activity interventions in hospital settings.

Methods
Four databases were searched until November 2023 for RCTs evaluating the effectiveness of physical activity interventions with adults aged ≥50 years in acute and subacute inpatient hospital settings, which included measurement of physical activity. Data extracted included study population characteristics, physical activity outcomes measured, and measurement tools used.

Results
After screening (n=17,114), 30 RCTs were included. The majority of RCTs were conducted in subacute rehabilitation (40%) and acute surgical wards (27%), and excluded participants with mobility impairment (67%) and cognitive impairment (67%). Almost all studies used devices, such as accelerometers, to measure physical activity (67%), with step count the main physical activity outcome measured (63%).

Conclusions
Most RCTS used accelerometers to measure physical activity and excluded patients with mobility and cognitive impairment. Almost two-thirds focussed on measurement of steps. Given that hospitalised older adults have high levels of mobility impairment and cognitive deficits, it is unclear whether results of included trials are generalisable to this population, and whether the physical activity outcomes and measurement tools used reflect their capabilities. Alternatives for measuring physical activity in hospitalised older adults should be explored.