title: Intracranial pressure monitoring and inpatient mortality in severe traumatic brain injury: A propensity score-matched analysis.
abstract: BACKGROUND
  Although intracranial pressure (ICP) monitoring in severe traumatic brain injury (TBI) is recommended by the Brain Trauma Foundation, the benefits remain controversial. We sought to determine the impact of ICP monitor placement on inpatient mortality within a regional trauma system after correcting for selection bias through propensity score matching.
  
  
  METHODS
  Data were collected on all severe TBI cases presenting to 14 trauma centers during the 2-year study period (2009-2010). Inclusion criteria were as follows: blunt injury, Glasgow Coma Scale (GCS) score of 8 or lower in the emergency department, and abnormal intracranial findings on head computed tomography (CT). Two separate multivariate logistic regression models were used to predict ICP monitor placement and inpatient mortality after controlling for demographics, severity of injury, comorbidities, and TBI-specific variables (GCS score, pupil reactivity, international normalized ratio, and nine specific head CT findings). To account for selection bias, we developed a propensity score-matched model to estimate the "true" effect of ICP monitoring on in-hospital mortality.
  
  
  RESULTS
  A total of 844 patients met inclusion criteria; 22 died on arrival to the emergency department. Inpatient mortality was 38.8%; 46.0% of the patients underwent ICP monitor placement. Unadjusted mortality rates were significantly lower in the ICP monitoring group (30.7% vs. 45.7%, p < 0.001). ICP monitor placement was positively associated with CT findings of subdural hematoma, intraparenchymal contusion, and mass effect and negatively associated with age, alcoholism, and elevated international normalized ratio. After adjusting for selection bias via propensity score matching, ICP monitor placement was associated with an 8.3 percentage point reduction in the risk-adjusted mortality rate.
  
  
  CONCLUSIONS
  ICP monitor placement occurred in only 46% of eligible patients but was associated with significantly decreased mortality after adjusting for baseline risk profile and the propensity to undergo monitoring. As the individual impact of ICP monitoring may vary, future efforts must determine who stands to benefit from invasive monitoring techniques.
  
  
  METHODS
  Therapeutic/care management study, level III.
authors.affiliation: From the Departments of Surgery (A.J.D., G.D.S., H.G.C., M.C., M.M.R., M.M.-G., C.Y.K.), and Neurosurgery (D.M.), David Geffen School of Medicine, and Robert Wood Johnson Clinical Scholars Program (A.J.D., G.D.S.), UCLA; VA Greater Los Angeles Healthcare System (A.J.D., M.M.R., M.M.-G., C.Y.K.); Department of Neurosurgery (J.P.G.), University of Southern California; and Emergency Medical Services Agency (C.P., D.G.), Department of Health Services, County of Los Angeles, Los Angeles, California.
authors.forename: Aaron J
authors.initials: AJ
authors.lastname: Dawes
authors.forename: Greg D
authors.initials: GD
authors.lastname: Sacks
authors.forename: H Gill
authors.initials: HG
authors.lastname: Cryer
authors.forename: J Peter
authors.initials: JP
authors.lastname: Gruen
authors.forename: Christy
authors.initials: C
authors.lastname: Preston
authors.forename: Deidre
authors.initials: D
authors.lastname: Gorospe
authors.forename: Marilyn
authors.initials: M
authors.lastname: Cohen
authors.forename: David L
authors.initials: DL
authors.lastname: McArthur
authors.forename: Marcia M
authors.initials: MM
authors.lastname: Russell
authors.forename: Melinda
authors.initials: M
authors.lastname: Maggard-Gibbons
authors.forename: Clifford Y
authors.initials: CY
authors.lastname: Ko
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000150:complications* / Q000401:mortality; D015897:Comorbidity; D005260:Female; D015600:Glasgow Coma Scale; D017052:Hospital Mortality; D006801:Humans; D015601:Injury Severity Score; D007297:Inpatients; D019934:International Normalized Ratio; D019586:Intracranial Hypertension / Q000209:etiology* / Q000401:mortality; D007427:Intracranial Pressure; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D057216:Propensity Score; D011446:Prospective Studies; D012042:Registries; D014057:Tomography, X-Ray Computed; D014193:Trauma Centers; D014949:Wounds, Nonpenetrating / Q000150:complications*