title: Meaningful change and responsiveness in common physical performance measures in older adults.
abstract: OBJECTIVE
  To estimate the magnitude of small meaningful and substantial individual change in physical performance measures and evaluate their responsiveness.
  
  
  METHODS
  Secondary data analyses using distribution- and anchor-based methods to determine meaningful change.
  
  
  METHODS
  Secondary analysis of data from an observational study and clinical trials of community-dwelling older people and subacute stroke survivors.
  
  
  METHODS
  Older adults with mobility disabilities in a strength training trial (n=100), subacute stroke survivors in an intervention trial (n=100), and a prospective cohort of community-dwelling older people (n=492).
  
  
  METHODS
  Gait speed, Short Physical Performance Battery (SPPB), 6-minute-walk distance (6MWD), and self-reported mobility.
  
  
  RESULTS
  Most small meaningful change estimates ranged from 0.04 to 0.06 m/s for gait speed, 0.27 to 0.55 points for SPPB, and 19 to 22 m for 6MWD. Most substantial change estimates ranged from 0.08 to 0.14 m/s for gait speed, 0.99 to 1.34 points for SPPB, and 47 to 49 m for 6MWD. Based on responsiveness indices, per-group sample sizes for clinical trials ranged from 13 to 42 for substantial change and 71 to 161 for small meaningful change.
  
  
  CONCLUSIONS
  Best initial estimates of small meaningful change are near 0.05 m/s for gait speed, 0.5 points for SPPB, and 20 m for 6MWD and of substantial change are near 0.10 m/s for gait speed, 1.0 point for SPPB, and 50 m for 6MWD. For clinical use, substantial change in these measures and small change in gait speed and 6MWD, but not SPPB, are detectable. For research use, these measures yield feasible sample sizes for detecting meaningful change.
authors.affiliation: Division of Geriatric Medicine and Department of Biostatistics, Univeristy of Pittsburgh, 3471 Fifth Avenue, Pittsburgh, PA 15213, USA. pereras@dom.pitt.edu
authors.forename: Subashan
authors.initials: S
authors.lastname: Perera
authors.forename: Samir H
authors.initials: SH
authors.lastname: Mody
authors.forename: Richard C
authors.initials: RC
authors.lastname: Woodman
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Studenski
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005080:Exercise Test; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D011597:Psychomotor Performance / Q000502:physiology*; D020127:Recovery of Function / Q000502:physiology*; D020521:Stroke / Q000503:physiopathology*; D000071939:Stroke Rehabilitation; D016138:Walking / Q000502:physiology*