title: A Novel Approach to Identifying Trajectories of Mobility Change in Older Adults.
abstract: OBJECTIVE
  To validate trajectories of late-life mobility change using a novel approach designed to overcome the constraints of modest sample size and few follow-up time points.
  
  
  METHODS
  Using clinical reasoning and distribution-based methodology, we identified trajectories of mobility change (Late Life Function and Disability Instrument) across 2 years in 391 participants age ≥65 years from a prospective cohort study designed to identify modifiable impairments predictive of mobility in late-life. We validated our approach using model fit indices and comparing baseline mobility-related factors between trajectories.
  
  
  RESULTS
  Model fit indices confirmed that the optimal number of trajectories were between 4 and 6. Mobility-related factors varied across trajectories with the most unfavorable values in poor mobility trajectories and the most favorable in high mobility trajectories. These factors included leg strength, trunk extension endurance, knee flexion range of motion, limb velocity, physical performance measures, and the number and prevalence of medical conditions including osteoarthritis and back pain.
  
  
  CONCLUSIONS
  Our findings support the validity of this approach and may facilitate the investigation of a broader scope of research questions within aging populations of varied sizes and traits.
authors.affiliation: New England GRECC, Boston VA Healthcare System, Boston, MA, United States of America.|Harvard Medical School, Cambridge, MA, United States of America.|Spaulding Rehabilitation Hospital, Cambridge, MA, United States of America.
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Ward
authors.affiliation: School of Rehabilitation Science, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Marla K
authors.initials: MK
authors.lastname: Beauchamp
authors.affiliation: Health and Disability Research Institute, Boston University School of Public Health, Boston, MA, United States of America.
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Latham
authors.affiliation: Harvard Medical School, Cambridge, MA, United States of America.|College of Nursing and Health Sciences, University of Massachusetts Boston, Boston, MA, United States of America.
authors.forename: Suzanne G
authors.initials: SG
authors.lastname: Leveille
authors.affiliation: Harvard Medical School, Cambridge, MA, United States of America.|Massachusetts General Hospital, Boston, MA, United States of America.
authors.forename: Sanja
authors.initials: S
authors.lastname: Percac-Lima
authors.affiliation: Spaulding Rehabilitation Hospital, Cambridge, MA, United States of America.|Harvard Medical School, Cambridge, MA, United States of America.
authors.forename: Laura
authors.initials: L
authors.lastname: Kurlinski
authors.affiliation: Health and Disability Research Institute, Boston University School of Public Health, Boston, MA, United States of America.
authors.forename: Pengsheng
authors.initials: P
authors.lastname: Ni
authors.affiliation: Spaulding Rehabilitation Hospital, Cambridge, MA, United States of America.|Harvard Medical School, Cambridge, MA, United States of America.
authors.forename: Richard
authors.initials: R
authors.lastname: Goldstein
authors.affiliation: Health and Disability Research Institute, Boston University School of Public Health, Boston, MA, United States of America.
authors.forename: Alan M
authors.initials: AM
authors.lastname: Jette
authors.affiliation: New England GRECC, Boston VA Healthcare System, Boston, MA, United States of America.|Harvard Medical School, Cambridge, MA, United States of America.|Spaulding Rehabilitation Hospital, Cambridge, MA, United States of America.
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Bean
mesh_terms: D000368:Aged; D000375:Aging / Q000502:physiology*; D001416:Back Pain / Q000453:epidemiology; D006801:Humans; D051346:Mobility Limitation; D053580:Muscle Strength; D010003:Osteoarthritis / Q000453:epidemiology; D010807:Physical Endurance