title: Limited predictive power of hospitalization variables for long-term cognitive prognosis in adult patients with severe traumatic brain injury.
abstract: OBJECTIVE
  Traumatic brain injury (TBI) is a main cause of mortality and morbidity. Association studies between hospitalization variables and cognitive impairment after TBI are frequently retrospective, including non-consecutive patients showing variable degrees of TBI severity, and poor management of missing (drop out) cases.
  
  
  METHODS
  We assessed prospectively the demographic and hospitalization variables of 234 consecutive patients with severe TBI (admission Glasgow Coma Scale [GCS] ≤8) and determined their independent association with cognitive performance in a representative sample (n = 46) of surviving patients (n = 172) evaluated 3 (±1.8) years after hospitalization.
  
  
  RESULTS
  In all, 85% of patients were male and the mean age was 34 (SD ±13) years. The education level was 9 (±4.7) years. As expected, education and age showed a moderately to strong linear relationship with the cognitive performance in 14 of 15 neuropsychological tests (R coefficient = 0.6-0.8). The cognitive test scores were not independently associated with gender, admission GCS, associated trauma, and Marshal CT classification. Admission-elevated blood glucose levels and the presence of sub-arachnoid haemorrhage were independently associated with lower scores on Rey Auditory Verbal Learning retention and Logical Memory-I tests, respectively.
  
  
  CONCLUSIONS
  After correction for education and age distribution, the variables that are commonly associated with mortality or Glasgow Outcome Scale including admission pupils' examination, Marshal CT Classification, GCS, and serum glucose showed a limited predictive power for long-term cognitive prognosis. Identification of clinical, radiological, and laboratory variables as well as new biomarkers independently associated with cognitive outcome remains an important challenge for further work involving severe TBI patients.
authors.affiliation: Centro de Neurociências Aplicadas (CeNAp), Hospital Universitário (HU), Universidade Federal de Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil.
authors.forename: Maria Emília Rodrigues
authors.initials: ME
authors.lastname: de Oliveira Thais
authors.forename: Gisele
authors.initials: G
authors.lastname: Cavallazzi
authors.forename: Douglas Afonso
authors.initials: DA
authors.lastname: Formolo
authors.forename: Lucas D'Ávila
authors.initials: LD
authors.lastname: de Castro
authors.forename: Roseli
authors.initials: R
authors.lastname: Schmoeller
authors.forename: Ricardo
authors.initials: R
authors.lastname: Guarnieri
authors.forename: Marcelo Liborio
authors.initials: ML
authors.lastname: Schwarzbold
authors.forename: Alexandre Paim
authors.initials: AP
authors.lastname: Diaz
authors.forename: Alexandre
authors.initials: A
authors.lastname: Hohl
authors.forename: Rui D S
authors.initials: RD
authors.lastname: Prediger
authors.forename: Maria Joana
authors.initials: MJ
authors.lastname: Mader
authors.forename: Marcelo Neves
authors.initials: MN
authors.lastname: Linhares
authors.forename: Angelica
authors.initials: A
authors.lastname: Staniloiu
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Markowitsch
authors.forename: Roger
authors.initials: R
authors.lastname: Walz
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology; D001930:Brain Injuries / Q000150:complications*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D015600:Glasgow Coma Scale; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007362:Intensive Care Units; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011379:Prognosis