To the knowledge of the authors, this is the first investigation to provide objective quantitative information on the walking behavior of older adults hospitalized for acute illness. Ambulation overall was remarkably low. On average, patients spent 4.1% of their time walking. Ambulation appeared to correspond well to the presumed recovery process and improvements in physiological health. Patients with shorter lengths of stay tended to ambulate more on the first complete day of hospitalization and to have a markedly greater increase in mobility on the second day than patients with longer lengths of stay. There were no significant differences in mean daily steps according to illness severity or reason for admission. Factors associated with the lowest ambulatory activity were primarily related to prior functional status, a bed rest order at hospital admission, delirium, and prolonged length of stay.
Published research on the ambulatory activity of community-living older adults provides some perspective on the levels of ambulation observed. A recent systematic review of number of pedometer-assessed steps taken per day by adults reported that persons aged 65 and older average 6,566 (95% confidence interval = 4,897–8,233) steps per day.19
Other pedometer-based studies generally report estimates in the range of 6,000 to 8,500 steps for this age group.20
In a small sample of older adults with functional limitations, a mean of 7,681.5 steps per day was reported using the same type of accelerometer as in the current study.12
The assessment of patient activity has historically been challenging. Methods have typically relied on nurse reports, chart reviews of physician orders, or direct observation in hallways.9,21
These approaches have inherent limitations. For example, transferring or walking in the hospital is often a brief activity, mostly done within the patient’s room.9
Hospital staff or surveys of location would easily miss these activities, especially if the patient was mobility independent.11
The SAM used in the current study was able to unobtrusively and continuously measure patient ambulation during an acute stay. These findings should encourage continued development of patient care applications for motion sensor technology. It has previously been demonstrated that this kind of information can be transmitted, in the hospital, wire-lessly to a central hub.8
Although additional research is needed on the feasibility of incorporating these data into the patient’s electronic medical record, mobility-related information would then be viewable in real time, with past history.
It is likely that easy access to patient activity data is essential to increasing awareness of healthcare providers regarding the potential consequences of low mobility during an acute stay. One study showed that the amount of time older patients with acute medical illnesses were limited to a bed or chair was an independent predictor of decline in ADLs, even after controlling for preadmission ADL impairment and illness severity.6
Although some inactivity during acute illness may not be avoidable or inappropriate, data from the current study also suggest that low mobility may be an underlying common pathway to functional decline in many geriatric patients.
This study has some limitations. First, data were collected on an ACE unit and therefore may not be representative of the hospital experience of older patients admitted to a traditional hospital ward. The physical environment of an ACE unit is designed to promote ambulation and provide incentive for patients to increase mobility and participate in activities during their hospital stay. ACE units employ a pre-habilitation model of acute care by using large congregate rooms and a prepared environment8
(e.g., hallways have reduced-glare lighting and grab bars and are carpeted). In this context, the findings regarding low ambulatory activity may be conservative because traditional hospital units may be less conducive to walking. Second, wearing the SAM could have influenced how much patients in the study walked, although the SAM provides no direct knowledge of results, and patients were instructed not to walk any more or less than they otherwise would while they were wearing the SAM.
In conclusion, ambulatory activity was low in the geriatric patients studied. How this walking behavior compares with that of younger patient populations during an acute stay with similar clinical profiles will require further study. Accelerometer technology shows potential for quantifying ambulation and patterns of activity of older hospitalized adults. Objective information on patient mobility may increase understanding of the level of ambulation required to maintain function while allowing patients to recover from their acute illness, develop appropriate standards of care for mobility in hospital, and influence policy decisions regarding hospital processes that affect mobility.