Mobility activity and its value as a prognostic indicator of survival in hospitalized older adults

Abstract

Objectives: To objectively assess total steps and minutes active in the first and last 24 hours of hospitalization and to examine associations with survival after discharge in hospitalized older adults.

Design: A prospective study.

Setting: A 20-bed Acute Care for Elders (ACE) hospital unit.

Participants: Two hundred twenty-four older adults admitted to an ACE hospital unit.

Measurements: An activity monitor was used to collect information on total steps and minutes of activity in the first and last 24 hours of hospitalization. The main outcome was 2-year survival from hospital discharge date.

Results: Participants were active for approximately 80 minutes in the first 24 hours of hospitalization. Participants aged 65-84 were active approximately 28 minutes more in the last 24 hours of hospitalization, but activity levels were essentially unchanged for those aged 85 and older. The median step count for participants was low, with a median of 478 steps in the first 24 hours of hospitalization and 846 in the last 24 hours. Multivariate survival models showed that, in the first and last 24 hours of hospitalization, each 100-step increase was associated with a 2% (hazard ratio (HR) = 0.98, 95% confidence interval (CI) = 0.96-1.00) and 3% (HR = 0.97, 95% CI = 0.94-0.99) lower risk of death over 2 years, respectively. A decline in steps from first to last 24 hours of hospitalization was associated with a more than four times greater risk of death (HR = 4.21, 95% CI = 1.65-10.77) 2 years after discharge.

Conclusion: Accelerometers could provide meaningful information about walking activity. The ability to apply objective information about the individual's functional status to improve the delivery of health care and health outcomes is important.

Conflict of interest statement

Conflict of Interest: The authors are not aware of any affiliations, memberships, funding, or financial holdings that might be perceived as affecting the objectivity of this review.

© 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

Figures

Figure 1

Enrollment Flow Diagram (N = 224).

Figure 2

Scatterplots of Steps in the First and Last 24-hrs of Hospitalization for the Total Sample (Figure 2a), and for Patients with a Step Count of 2000 or Fewer Steps in the first 24-hours of hospitalization (Figure 2b.) (N =224).

Figure 3

Unadjusted Survival Curves Assessing Death 2-years Post Discharge by Steps in the First (Figure 3a.) and Last (Figure 3b.) 24-Hours of Hospitalization (N = 224).