title: Prognostic value of usual gait speed in well-functioning older people--results from the Health, Aging and Body Composition Study.
abstract: OBJECTIVE
  To define clinically relevant cutpoints for usual gait speed and to investigate their predictive value for health-related events in older persons.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Health, Aging and Body Composition Study.
  
  
  METHODS
  Three thousand forty-seven well-functioning older persons (mean age 74.2).
  
  
  METHODS
  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 (> or = 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Aging and Geriatric Research, College of Medicine, Institute on Aging, University of Florida, Gainesville, Florida 32608, USA. mcesari@aging.ufl.edu
authors.forename: Matteo
authors.initials: M
authors.lastname: Cesari
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kritchevsky
authors.forename: Brenda W H J
authors.initials: BW
authors.lastname: Penninx
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Nicklas
authors.forename: Eleanor M
authors.initials: EM
authors.lastname: Simonsick
authors.forename: Anne B
authors.initials: AB
authors.lastname: Newman
authors.forename: Frances A
authors.initials: FA
authors.lastname: Tylavsky
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Brach
authors.forename: Suzanne
authors.initials: S
authors.lastname: Satterfield
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Bauer
authors.forename: Marjolein
authors.initials: M
authors.lastname: Visser
authors.forename: Susan M
authors.initials: SM
authors.lastname: Rubin
authors.forename: Tamara B
authors.initials: TB
authors.lastname: Harris
authors.forename: Marco
authors.initials: M
authors.lastname: Pahor
mesh_terms: D000054:Acceleration; D000203:Activities of Daily Living / Q000145:classification; D000368:Aged; D000375:Aging / Q000502:physiology*; D001823:Body Composition / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D011379:Prognosis; D012016:Reference Values; D013223:Statistics as Topic; D016019:Survival Analysis