title: Two-Year Trajectory of Fall Risk in People With Parkinson Disease: A Latent Class Analysis.
abstract: OBJECTIVE
  To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD).
  
  
  METHODS
  Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories.
  
  
  METHODS
  Assessments were conducted at 1 of 4 universities.
  
  
  METHODS
  Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230).
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed.
  
  
  RESULTS
  The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (P<.001). Fluctuating fall risk (posterior probability <0.8 of belonging to any trajectory) was found in only 22.6% of the sample, most commonly among individuals who were transitioning to PIGD predominance.
  
  
  CONCLUSIONS
  Regardless of their baseline characteristics, most participants had clear and stable fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD.
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, UT; The George Institute for Global Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.
authors.forename: Serene S
authors.initials: SS
authors.lastname: Paul
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, UT.
authors.forename: Anne
authors.initials: A
authors.lastname: Thackeray
authors.affiliation: Program in Physical Therapy, Washington University School of Medicine in St Louis, St Louis, MO; Department of Neurology, Washington University School of Medicine in St Louis, St Louis, MO.
authors.forename: Ryan P
authors.initials: RP
authors.lastname: Duncan
authors.affiliation: Department of Physical Therapy, University of New England, Portland, ME.
authors.forename: James T
authors.initials: JT
authors.lastname: Cavanaugh
authors.affiliation: Department of Physical Therapy and Athletic Training, Boston University, Boston, MA.
authors.forename: Theresa D
authors.initials: TD
authors.lastname: Ellis
authors.affiliation: Program in Physical Therapy, Washington University School of Medicine in St Louis, St Louis, MO; Department of Neurology, Washington University School of Medicine in St Louis, St Louis, MO; Department of Anatomy and Neurobiology, Washington University School of Medicine in St Louis, St Louis, MO.
authors.forename: Gammon M
authors.initials: GM
authors.lastname: Earhart
authors.affiliation: Department of Physical Therapy, University of Alabama at Birmingham School of Health Professions, Birmingham, AL.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Ford
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, UT.
authors.forename: K Bo
authors.initials: KB
authors.lastname: Foreman
authors.affiliation: Department of Physical Therapy, University of Utah, Salt Lake City, UT. Electronic address: lee.dibble@hsc.utah.edu.
authors.forename: Leland E
authors.initials: LE
authors.lastname: Dibble
mesh_terms: D000058:Accidental Falls; D000368:Aged; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000503:physiopathology*; D018570:Risk Assessment; D012307:Risk Factors
keywords: Accidental falls; Gait; Longitudinal studies; Parkinson disease; Rehabilitation; Risk