title: Trajectories of combined laboratory- and real world-based speed of processing in community-dwelling older adults.
abstract: OBJECTIVE
  To characterize the trajectories of laboratory- and real world-based speed of processing (SOP) over 5 years using finite latent growth mixture modeling, and to explore associated baseline individual-level predictors and functional outcomes in 2,802 community-dwelling older adults from the Advanced Cognitive Training for Independent and Vital Elderly cohort.
  
  
  METHODS
  Laboratory- and real world-based SOP and functional outcomes were assessed over 5 years, and candidate individual-level predictors were collected at baseline.
  
  
  RESULTS
  After controlling for intervention assignment and demographic information, 4 distinct trajectories were identified: 4.6% of older adults had poor laboratory-based SOP and very poor real world-based SOP that both declined substantially over time; 17.9% had poor laboratory- and real world-based SOP that declined moderately; 38.7% had neutral laboratory- and real world-based SOP that maintained stable; and 37.9% had good laboratory- and real world-based SOP that declined slightly. Non-White, depression, subjective memory complaints, and vascular factors predicted the trajectories. The trajectories significantly differed in the rate of decline in basic activities of daily living, instrumental activities of daily living, and grip strength over time.
  
  
  CONCLUSIONS
  Heterogeneous trajectories of SOP exist in old age. Future interventions addressing SOP should target the vulnerable group with poor SOP over time.
authors.affiliation: School of Nursing, University of Rochester Medical Center, HWH 2w128, 601 Elmwood Ave., Rochester, NY 14642, USA. vankee_lin@urmc.rochester.edu
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
authors.forename: Ding-Geng Din
authors.initials: DG
authors.lastname: Chen
authors.forename: David
authors.initials: D
authors.lastname: Vance
authors.forename: Mark
authors.initials: M
authors.lastname: Mapstone
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology*; D000368:Aged; D000375:Aging / Q000502:physiology / Q000523:psychology*; D003071:Cognition / Q000145:classification / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D015577:Geriatric Assessment / Q000145:classification; D006801:Humans; D008297:Male; D008960:Models, Psychological; D011237:Predictive Value of Tests; D016032:Randomized Controlled Trials as Topic / Q000379:methods / Q000523:psychology; D011930:Reaction Time / Q000502:physiology; D012111:Residence Characteristics