title: Diagnostic accuracy of hyperbilirubinaemia in anticipating appendicitis and its severity.
abstract: BACKGROUND
  Hyperbilirubinaemia is reported to be a positive predictor in diagnosing appendicitis and especially appendiceal perforation. We, therefore, analysed the diagnostic accuracy of serum bilirubin in anticipating appendicitis and its severity.
  
  
  METHODS
  All consecutive patients undergoing appendectomy for suspected appendicitis from May 2009 to August 2011 were analysed. Patients were classified based on final histopathological findings into the groups: no appendiceal inflammation, non-perforated appendicitis and perforated appendicitis. Primary outcome was the diagnostic accuracy of serum bilirubin levels in discriminating between no appendiceal inflammation and any appendicitis (perforated and non-perforated appendicitis) and non-perforated and perforated appendicitis.
  
  
  RESULTS
  Of 493 analysed patients, 125 (25%) had no appendiceal inflammation, 312 (64%) had non-perforated appendicitis and 56 (11%) had perforated appendicitis. The proportion of patients with bilirubin elevation (>1.1 mg/dL) was different between those with no appendiceal inflammation (14%) and any appendicitis (36%) (p<0.0001), and between non-perforated appendicitis and perforated appendicitis 48% (p=0.04). However, the positive and negative likelihood ratios (LRs) for an elevated bilirubin were poor at discriminating the groups: no appendiceal inflammation versus any appendicitis (LR+ 2.62 (95% CI 1.65 to 4.16) and LR- 0.75 (95% CI 0.67 to 0.83)) and non-perforated appendicitis versus perforated appendicitis (LR+ estimate 1.74 (95% CI 1.28 to 2.38) and LR- 0.72 (95% CI 0.55 to 0.93)).
  
  
  CONCLUSIONS
  Hyperbilirubinaemia is present in acute appendicitis but has a low diagnostic accuracy in discriminating between any appendicitis versus no appendiceal inflammation and perforated versus non-perforated appendicitis and is, therefore, of limited value in clinical routine.
  
  
  BACKGROUND
  NCT01698099.
authors.affiliation: Working Group for Surgical Technology and Training, Clinic for Visceral, General and Transplant Surgery, Tübingen University Hospital, Tübingen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Muller
authors.affiliation: Working Group for Surgical Technology and Training, Clinic for Visceral, General and Transplant Surgery, Tübingen University Hospital, Tübingen, Germany.
authors.forename: Claudius
authors.initials: C
authors.lastname: Falch
authors.affiliation: Working Group for Surgical Technology and Training, Clinic for Visceral, General and Transplant Surgery, Tübingen University Hospital, Tübingen, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Axt
authors.affiliation: Working Group for Surgical Technology and Training, Clinic for Visceral, General and Transplant Surgery, Tübingen University Hospital, Tübingen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Wilhelm
authors.affiliation: Working Group for Surgical Technology and Training, Clinic for Visceral, General and Transplant Surgery, Tübingen University Hospital, Tübingen, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Hein
authors.affiliation: Working Group for Surgical Technology and Training, Clinic for Visceral, General and Transplant Surgery, Tübingen University Hospital, Tübingen, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Königsrainer
authors.affiliation: Working Group for Surgical Technology and Training, Clinic for Visceral, General and Transplant Surgery, Tübingen University Hospital, Tübingen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kirschniak
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001062:Appendectomy; D001064:Appendicitis / Q000097:blood* / Q000473:pathology* / Q000601:surgery; D001663:Bilirubin / Q000097:blood*; D005260:Female; D006801:Humans; D006932:Hyperbilirubinemia / Q000150:complications* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D001663:Bilirubin
keywords: abdomen; abdomen- non trauma, gastro-intestinal; diagnosis; general