title: Identifying Neurocognitive Decline at 36 Months among HIV-Positive Participants in the CHARTER Cohort Using Group-Based Trajectory Analysis.
abstract: While HIV-associated neurocognitive impairment remains common despite the widespread use of combined antiretroviral therapy (cART), there have been relatively few studies investigating the trajectories of neurocognitive change in longitudinal NeuroAIDS studies.
  
  
  
  To estimate the magnitude and pattern of neurocognitive change over the first 3 years of follow-up using Group-Based Trajectory Analysis (GBTA) applied to participants in the longitudinal arm of the CHARTER cohort.
  
  
  
  The study population consisted of 701 CHARTER participants who underwent neuropsychological (NP) testing on at least 2 occasions. Raw test scores on 15 NP measures were modeled using GBTA. Each trajectory was categorized as stable, improved or declined, according to two different criteria for change (whether the magnitude of the estimated change at 36 months differed ≥ 0.5 standard deviations from baseline value or changed by > the standard error of measurement estimated at times 1 and 2). Individuals who declined on one or more NP measures were categorized as decliners.
  
  
  
  Overall, 111 individuals (15.8%) declined on at least one NP test over 36 months, with the vast majority showing decline on a single NP test (93/111-83.8%). The posterior probability of group assignment was high in most participants (71%) after only 2 sessions, and in the overwhelming majority of those with 3+ sessions. Heterogeneity of trajectories was the norm rather than the exception. Individuals who declined had, on average, worse baseline NP performance on every test, were older, had a longer duration of HIV infection and more follow-up sessions.
  
  
  
  The present study identified heterogeneous trajectories over 3 years across 15 NP raw test scores using GBTA. Cognitive decline was observed in only a small subset of this study cohort. Decliners had demographics and HIV characteristics that have been previously associated with cognitive decline, suggesting clinical validity for the method.
authors.affiliation: Department of Psychiatry, McGill University, McGill University Health Centre, Montreal, Canada.
authors.forename: Marie-Josée
authors.initials: MJ
authors.lastname: Brouillette
authors.affiliation: Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Canada.|Child Health Evaluative Sciences, Hospital for Sick Children, Toronto, Canada.
authors.forename: Tracy
authors.initials: T
authors.lastname: Yuen
authors.affiliation: Department of Neurology & Neurosurgery, McGill University, Montreal Neurological Institute, Montreal, Canada.
authors.forename: Lesley K
authors.initials: LK
authors.lastname: Fellows
authors.affiliation: University of New South Wales, St. Vincent's Hospital Sydney, Neuroscience Research Australia, Sydney, Australia.
authors.forename: Lucette A
authors.initials: LA
authors.lastname: Cysique
authors.affiliation: HIV Neurobehavioural Research Centre, University of California San Diego, San Diego, California, United States Of America.
authors.forename: Robert K
authors.initials: RK
authors.lastname: Heaton
authors.affiliation: Division of Clinical Epidemiology, McGill University Health Centre, Montreal, Canada.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Mayo
mesh_terms: D015526:AIDS Dementia Complex / Q000175:diagnosis / Q000453:epidemiology*; D000465:Algorithms; D003071:Cognition; D015331:Cohort Studies; D006801:Humans; D008137:Longitudinal Studies