title: Examining late-life functional limitation trajectories and their associations with underlying onset, recovery, and mortality.
abstract: OBJECTIVE
  Identify common trajectories of physical functional limitation and mortality among Taiwanese 50 and older as they age, link these to underlying transitions in onset, recovery, and mortality, and assess associations between trajectories and a set of risk factors.
  
  
  METHODS
  Longitudinal data from 4 waves of the Survey of Health and Living Status of the Middle-Aged and Elderly in Taiwan, collected between 1996 and 2007, are analyzed using a summary measure indicating difficulty with one or more of 7 physical functions. A group-based trajectory model identifies common trajectories. Shorter term transition probabilities that underlie multiperiod trajectories are examined. Multinomial regression associates risk factors with trajectory group membership.
  
  
  RESULTS
  Best fitting the data is a model with 3 groups characterized as early, mid, and late onset of limitation. Roughly half the population follows the trajectory of mid onset and a quarter each of the other 2. Females and those least educated are most likely to belong to the early-onset group.
  
  
  CONCLUSIONS
  The analysis advances understanding of late-life functioning by focusing on the heterogeneity of functional limitation experience, appropriately accounting for the relation between functional limitation and mortality and linking long-term patterns with short-term changes in functional limitation.
authors: Correspondence should be addressed to Zachary Zimmer, Department of Social and Behavioral Sciences, University of California San Francisco, Laurel Heights Campus, Box 0612, San Francisco, CA 94143-0612. E-mail: zachary.zimmer@ucsf.edu.
authors: Zachary
authors: Z
authors: Zimmer
authors: Linda G
authors: LG
authors: Martin
authors: Bobby L
authors: BL
authors: Jones
authors: Daniel S
authors: DS
authors: Nagin
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000375:Aging / Q000473:pathology / Q000502:physiology*; D004185:Disability Evaluation; D018450:Disease Progression; D004522:Educational Status; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009026:Mortality; D020127:Recovery of Function / Q000502:physiology; D012737:Sex Factors; D013624:Taiwan
keywords: Demography; Disability; Epidemiology; Functional health status.