title: Dynamics of functional aging based on latent-class trajectories of activities of daily living.
abstract: OBJECTIVE
  This study sought to identify and characterize major patterns of functional aging based on activities of daily living (ADL).
  
  
  METHODS
  We followed 754 community-living adults aged 70 years or older monthly for ADLs, instrumental ADLs, hospitalization and restricted activity over 10 years. A generalized growth mixture model was used to identify trajectories of ADL disability across seven 18-month intervals. Cumulative burdens of disability and morbidity from different trajectories were examined using a generalized estimating equation Poisson model.
  
  
  RESULTS
  Five distinct trajectories emerged. The predominant trajectory maintained ADL independence, with membership probability being 61.6%. The remaining trajectories either stayed at low (1 or 2 ADLs, 13.6%) or high (3 or 4 ADLs, 7.0%) levels of disability or declined gradually toward low (11.2%) or high (6.5%) disability. The independent trajectory was associated with the lowest burdens of disability and morbidity and a decreasing time trend of restricted activity, whereas the high disability trajectory demonstrated opposite trends. About 31% of the cohort remained in the same trajectory throughout the follow-up period.
  
  
  CONCLUSIONS
  The course of functional aging is heterogeneous and dynamic. Although most older adults maintain functional autonomy, some may experience persistent disability or progress toward severe disability with substantial morbidity.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA. ling.han@yale.edu
authors.forename: Ling
authors.initials: L
authors.lastname: Han
authors.forename: Heather
authors.initials: H
authors.lastname: Allore
authors.forename: Terrence
authors.initials: T
authors.lastname: Murphy
authors.forename: Thomas
authors.initials: T
authors.lastname: Gill
authors.forename: Peter
authors.initials: P
authors.lastname: Peduzzi
authors.forename: Haiqun
authors.initials: H
authors.lastname: Lin
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology* / Q000523:psychology; D001499:Bayes Theorem; D002908:Chronic Disease / Q000453:epidemiology / Q000534:rehabilitation*; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000534:rehabilitation*; D005260:Female; D015577:Geriatric Assessment; D006760:Hospitalization; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009017:Morbidity; D015995:Prevalence; D012959:Socioeconomic Factors; D013997:Time Factors