title: Glasgow Coma Scale score dominates the association between admission Sequential Organ Failure Assessment score and 30-day mortality in a mixed intensive care unit population.
abstract: OBJECTIVE
  The Sequential Organ Failure Assessment (SOFA) score, a measure of multiple-organ dysfunction syndrome, is used to predict mortality in critically ill patients by assigning equally weighted scores across 6 different organ systems. We hypothesized that specific organ systems would have a greater association with mortality than others.
  
  
  METHODS
  We retrospectively studied patients admitted over a period of 4.2 years to a mixed-profile intensive care unit (ICU). We recorded age and comorbidities, and calculated SOFA organ scores. The primary outcome was 30-day all-cause mortality. We determined which organ subscores of the SOFA score were most associated with mortality using multiple analytic methods: random forests, conditional inference trees, distanced-based clustering techniques, and logistic regression.
  
  
  METHODS
  A 24-bed mixed-profile adult ICU that cares for medical, surgical, and trauma (level 1) patients at an academic referral center.
  
  
  METHODS
  All patients' first admission to the study ICU during the study period.
  
  
  RESULTS
  We identified 9120 first admissions during the study period. Overall 30-day mortality was 12%. Multiple analytical methods all demonstrated that the best initial prediction variables were age and the central nervous system SOFA subscore, which is determined solely by Glasgow Coma Scale score.
  
  
  CONCLUSIONS
  In a mixed population of critically ill patients, the Glasgow Coma Scale score dominates the association between admission SOFA score and 30-day mortality. Future research into outcomes from multiple-organ dysfunction may benefit from new models for measuring organ dysfunction with special attention to neurologic dysfunction.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, University of Utah School of Medicine, Salt Lake City, UT.
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Knox
authors.affiliation: Division of Pulmonary and Critical Care Medicine, University of Utah School of Medicine, Salt Lake City, UT; Division of Pulmonary and Critical Care Medicine, Intermountain Medical Center, Murray, UT.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lanspa
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Intermountain Medical Center, Murray, UT.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Pratt
authors.affiliation: Homer Warner Center for Informatics Research, Intermountain Healthcare, Murray, UT.
authors.forename: Kathryn G
authors.initials: KG
authors.lastname: Kuttler
authors.affiliation: Clinical Intelligence and Decision Support, Kaiser-Permanente Southern California Medical Group, Palm Desert, CA.
authors.forename: Jason P
authors.initials: JP
authors.lastname: Jones
authors.affiliation: Division of Pulmonary and Critical Care Medicine, University of Utah School of Medicine, Salt Lake City, UT; Division of Pulmonary and Critical Care Medicine, Intermountain Medical Center, Murray, UT. Electronic address: Samuel.Brown@imail.org.
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Brown
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002423:Cause of Death; D003422:Critical Care / Q000706:statistics & numerical data*; D016638:Critical Illness; D005260:Female; D015600:Glasgow Coma Scale; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000401:mortality*; D063305:Organ Dysfunction Scores; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors
keywords: Classification trees; ICU; Multiple-organ dysfunction; Outcomes; Random forests; SOFA