Prognostic Value of Usual Gait Speed in Well-Functioning Older People: Results from the Health, Aging and Body Composition Study

Matteo Cesari, MD, PhD; Stephen B. Kritchevsky, PhD; Brenda W. H. J. Penninx, PhD; Barbara J. Nicklas, PhD; Eleanor M. Simonsick, PhD; Anne B. Newman, MD, MPH; Frances A. Tylavsky, DrPH; Jennifer S. Brach, PT, PhD, GCS; Suzanne Satterfield, MD, DrPH; Douglas C. Bauer, MD; Marjolein Visser, PhD; Susan M. Rubin, MPH; Tamara B. Harris, MD, MS; Marco Pahor, MD

Disclosures

J Am Geriatr Soc. 2005;53(10):1675-1680. 

In This Article

Abstract and Introduction

Objectives: To define clinically relevant cutpoints for usual gait speed and to investigate their predictive value for health-related events in older persons.
Design: Prospective cohort study.
Setting: Health, Aging and Body Composition Study.
Participants: Three thousand forty-seven well-functioning older persons (mean age 74.2).
Measurements: Usual gait speed on a 6-m course was assessed at baseline. Participants were randomly divided into two groups to identify (Sample A; n=2,031) and then validate (Sample B; n=1,016) usual gait-speed cutpoints. Rates of persistent lower extremity limitation events (mean follow-up 4.9 years) were calculated according to gait speed in Sample A. A cutpoint (defining high- (<1 m/s) and low risk (≥1 m/s) groups) was identified based on persistent lower extremity limitation events. The predictive value of the identified cutpoints for major health-related events (persistent severe lower extremity limitation, death, and hospitalization) was evaluated in Sample B using Cox regression analyses.
Results: A graded response was seen between risk groups and health-related outcomes. Participants in the high-risk group had a higher risk of persistent lower extremity limitation (rate ratio (RR)=2.20, 95% confidence interval (CI)=1.76-2.74), persistent severe lower extremity limitation (RR=2.29, 95% CI=1.63-3.20), death (RR=1.64, 95% CI=1.14-2.37), and hospitalization (RR=1.48, 95% CI=1.02-2.13) than those in the low-risk group.
Conclusion: Usual gait speed of less than 1 m/s identifies persons at high risk of health-related outcomes in well-functioning older people. Provision of a clinically meaningful cutpoint for usual gait speed may facilitate its use in clinical and research settings.

Clinicians have not widely adopted the use of performance-based measures to evaluate the functional status of older persons, possibly owing to the perception that these tests often require substantial space or special equipment or are unduly time consuming.[1,2] Moreover, previously defined cutpoints for physical performance measures, derived from distributions in specific populations,[2,3,4,5,6,7,8] might have limited applicability to the general population. Furthermore, the normal values of these measures remain undefined, which makes their clinical application difficult. A cutpoint indicating normal values has crucial importance in promoting the use of continuous markers in the clinical setting.

Of the available physical performance measures, usual gait speed may represent the one that is most suitable to be implemented in the standard clinical evaluation of older persons. Usual gait speed is a quick, inexpensive, and highly reliable measure of functional capacity that can be easily measured in the clinical setting.[9] Moreover, its well-documented predictive value for major health-related outcomes[10,11,12] makes it a useful screening tool to identify older persons at risk of events.

The purpose of the present study was to determine a cutpoint value for usual gait speed over a short (6-m) course using the Health, Aging and Body Composition Study (Health ABC) cohort. Because Health ABC enrolled a large sample of only well-functioning nondisabled older persons, it affords an excellent opportunity to establish the prognostic value of physical performance in older people and to provide an estimate of their normal values.

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