title: The clinical value of pathology tests and imaging study in the diagnosis of acute appendicitis.
abstract: OBJECTIVE
  To explore the diagnostic accuracy of acute appendicitis among different patient groups and evaluate the statistical diagnostic values of common pathology and imaging tests for the diagnosis of acute appendicitis.
  
  
  METHODS
  Proportions of histology-proven appendicitis in different patient groups. Statistical parameters including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (+LR), negative likelihood ratio (-LR) and diagnostic odds ratio (DOR) between the histology-proven appendicitis and abnormal results of U/S, CT, WCC, CRP, bilirubin, pancreatic, and combined test results of WCC and CRP.
  
  
  RESULTS
  Our data showed that up to 25.7% of patients underwent appendectomy has normal appendix. Appendicitis is often accurately diagnosed among male patients, up to 90.3% of the time, while misdiagnosis of appendicitis among young females (<40 years old) is significantly high, up to 30.9%. CT has high diagnostic performance index for appendicitis, sensitivity > 90%, and no individual pathology test out of those examined can rival the sensitivity of CT. Nevertheless, by examining the combined results of WCC and CRP, we found that abnormal results in one or both these yields sensitivity similar to CT scans in detecting acute appendicitis, up to 95%.
  
  
  CONCLUSIONS
  Young female patients have highest risk of being falsely diagnosed with acute appendicitis and hence unnecessary surgery. Bilirubin and lipase exhibit no correlations with acute appendicitis. Combined interpretation of WCC or CRP abnormal results yields competitive sensitivity as CT. Hencewe would suggest that, under the appropriate clinical context, one can use both WCC and CRP as a simple tool to support the diagnosis of appendicitis. If both tests show normal results, we would highly recommend considering alternative diagnosis.
authors: Department of Cardiology, The Canberra Hospital, Acton, Australian Capital Territory, Australia ANU Medical Australian National University, Acton, Australian Capital Territory, Australia.
authors: Ko-Chin
authors: KC
authors: Chen
authors: Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
authors: Alon
authors: A
authors: Arad
authors: Department of Biomedical Research, Taiwan National University, Taipei, Taiwan.
authors: Ko-Chien
authors: KC
authors: Chen
authors: Emergency Medicine, Townsville Hospital, Townsville, Queensland, Australia.
authors: Jonathan
authors: J
authors: Storrar
authors: Depatment of Applied Mathematics, Australian National University, Canberra, Australian Capital Territory, Australia.
authors: Andrew G
authors: AG
authors: Christy
mesh_terms: D000328:Adult; D000367:Age Factors; D001062:Appendectomy; D001064:Appendicitis / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D001663:Bilirubin / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008049:Lipase / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012737:Sex Factors; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D002097:C-Reactive Protein; D008049:Lipase; D001663:Bilirubin
keywords: Abdominal Pain; Appendicitis; Diagnosis of Appendicitis; Imaging for appendicitis; Pathology test for appendicitis