title: S100B serum protein cannot predict secondary intracranial haemorrhage after mild head injury in patients with low-dose acetylsalicylic acid prophylaxis.
abstract: BACKGROUND
  The goal of this study was to investigate if S100B serum protein could predict secondary intracranial haemorrhagic events (SIHEs) after mild head injury (mHI) in patients taking low-dose acetylsalicylic acid (LDA), making routinely repeated head computed tomography (RRHCT) scans unnecessary.
  
  
  METHODS
  Three hundred and eight-two patients with mHI, older than 60 years and taking LDA prophylaxis were enrolled. Primary head CT and RRHCT scans within 3 and 48 hours to trauma were performed. Additionally, S100B serum protein levels were evaluated at admission and predictive power for SIHEs was analysed.
  
  
  RESULTS
  Fifty-nine per cent were female and the mean age of all included patients was 81.8 ± 8.9 years. In four patients SIHEs were diagnosed. Sensitivity and the negative predictive value of S100B serum protein (cut-off value 0.10 µg l(-1)) were 75.0% and 98.6%, respectively. Specificity was 19.0% and the positive predictive value 1.0% (306 false positive values). In patients without bleeding, the median S100B value was 0.18 (IQR = 0.12-0.34) and in the ones with SIHEs, the median was 0.11 (IQR = 0.10-1.16) (p > 0.05). The discriminatory power of S100B in the ROC analysis was 0.399 (95% CI = 0.079-0.720; p > 0.05).
  
  
  CONCLUSIONS
  S100B cannot be considered as an effective diagnostic tool in the prediction or exclusion of SIHE in older patients with mHIs taking LDA prophylaxis.
authors.affiliation: a Department of Traumatology and Sports Injuries , Paracelsus Medical University , Salzburg , Austria .
authors.forename: Lukas
authors.initials: L
authors.lastname: Ernstbrunner
authors.affiliation: a Department of Traumatology and Sports Injuries , Paracelsus Medical University , Salzburg , Austria .
authors.forename: Gundobert
authors.initials: G
authors.lastname: Korn
authors.affiliation: b General Practitioner Office , Vienna , Austria , and .
authors.forename: Erich
authors.initials: E
authors.lastname: Ernstbrunner
authors.affiliation: a Department of Traumatology and Sports Injuries , Paracelsus Medical University , Salzburg , Austria .
authors.forename: Alexander
authors.initials: A
authors.lastname: Auffarth
authors.affiliation: a Department of Traumatology and Sports Injuries , Paracelsus Medical University , Salzburg , Austria .|c Department of Shoulder and Elbow Surgery , Atos Clinic , Munich , Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Tauber
authors.affiliation: a Department of Traumatology and Sports Injuries , Paracelsus Medical University , Salzburg , Austria .
authors.forename: Herbert
authors.initials: H
authors.lastname: Resch
authors.affiliation: a Department of Traumatology and Sports Injuries , Paracelsus Medical University , Salzburg , Austria .
authors.forename: Philipp
authors.initials: P
authors.lastname: Moroder
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001241:Aspirin / Q000008:administration & dosage*; D015415:Biomarkers / Q000097:blood; D006259:Craniocerebral Trauma / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D020300:Intracranial Hemorrhages / Q000097:blood* / Q000175:diagnosis / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D015415:Biomarkers; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human; D001241:Aspirin
keywords: Head computed tomography; receiver operating characteristic curve