title: An index predictive of cognitive outcome in retired professional American Football players with a history of sports concussion.
abstract: OBJECTIVE
  Various concussion characteristics and personal factors are associated with cognitive recovery in athletes. We developed an index based on concussion frequency, severity, and timeframe, as well as cognitive reserve (CR), and we assessed its predictive power regarding cognitive ability in retired professional football players.
  
  
  METHODS
  Data from 40 retired professional American football players were used in the current study. On average, participants had been retired from football for 20 years. Current neuropsychological performances, indicators of CR, concussion history, and play data were used to create an index for predicting cognitive outcome.
  
  
  RESULTS
  The sample displayed a range of concussions, concussion severities, seasons played, CR, and cognitive ability. Many of the participants demonstrated cognitive deficits. The index strongly predicted global cognitive ability (R(2) = .31). The index also predicted the number of areas of neuropsychological deficit, which varied as a function of the deficit classification system used (Heaton: R(2) = .15; Wechsler: R(2) = .28).
  
  
  CONCLUSIONS
  The current study demonstrated that a unique combination of CR, sports concussion, and game-related data can predict cognitive outcomes in participants who had been retired from professional American football for an average of 20 years. Such indices may prove to be useful for clinical decision making and research.
authors.affiliation: a Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center , Torrance , CA , USA.|b Department of Psychiatry and Biobehavioral Sciences , UCLA School of Medicine , Los Angeles , CA , USA.|c Division of Psychology, Department of Psychiatry , Harbor-UCLA Medical Center , Torrance , CA , USA.
authors.forename: Mathew J
authors.initials: MJ
authors.lastname: Wright
authors.affiliation: d Easton Center for Alzheimer's Disease Research, Department of Neurology , UCLA School of Medicine , Los Angeles , CA , USA.
authors.forename: Ellen
authors.initials: E
authors.lastname: Woo
authors.affiliation: a Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center , Torrance , CA , USA.|c Division of Psychology, Department of Psychiatry , Harbor-UCLA Medical Center , Torrance , CA , USA.
authors.forename: J Brandon
authors.initials: JB
authors.lastname: Birath
authors.affiliation: a Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center , Torrance , CA , USA.|c Division of Psychology, Department of Psychiatry , Harbor-UCLA Medical Center , Torrance , CA , USA.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Siders
authors.affiliation: e Brain Tumor Center & Pituitary Disorders Program, John Wayne Cancer Institute at Saint John's Health Center , Santa Monica , CA , USA.
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Kelly
authors.affiliation: a Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center , Torrance , CA , USA.|f Division of Endocrinology, Department of Medicine , Harbor-UCLA Medical Center , Torrance , CA , USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Wang
authors.affiliation: a Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center , Torrance , CA , USA.|f Division of Endocrinology, Department of Medicine , Harbor-UCLA Medical Center , Torrance , CA , USA.
authors.forename: Ronald
authors.initials: R
authors.lastname: Swerdloff
authors.affiliation: a Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center , Torrance , CA , USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Romero
authors.affiliation: b Department of Psychiatry and Biobehavioral Sciences , UCLA School of Medicine , Los Angeles , CA , USA.
authors.forename: Claudia
authors.initials: C
authors.lastname: Kernan
authors.affiliation: g Boston University School of Medicine , Boston , MA , USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Cantu
authors.affiliation: h Center for the Study of Retired Athletes of the University of North Carolina , Chapel Hill, NC , USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Guskiewicz
mesh_terms: D000328:Adult; D000368:Aged; D001265:Athletic Injuries / Q000150:complications*; D001924:Brain Concussion / Q000150:complications* / Q000209:etiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D058245:Cognitive Reserve / Q000502:physiology; D005260:Female; D005538:Football; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D012179:Retirement / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014481:United States
keywords: Cerebral concussion; Cognition; Cognitive reserve; Sports; Traumatic brain injury