title: The diagnostic dilemma of identifying perforated appendicitis.
abstract: BACKGROUND
  Despite extensive research, the classification of perforated (PA) versus nonperforated appendicitis (NPA) remains poorly defined. We hypothesize that the variability across specialties in the classification of appendicitis as PA or NPA may be associated with variation in clinical behavior as demonstrated by a variation in length of stay (LOS).
  
  
  METHODS
  Retrospective review of 1311 appendectomies over a 16-mo period from an independent children's hospital allowed a comparison of the diagnostic classification of appendicitis as PA or NPA based on radiology (R), operative (O), and pathology (P) reports. Three groups, P + O (n = 1241), P + R (n = 516), O + R (n = 512) were compared to identify interspecialty discordance in classification. The LOS was analyzed as a proxy for clinical behavior to test if the diagnostic classification was consistent with expected clinical behavior (NPA with LOS ≤48 h and PA with LOS >48 h).
  
  
  RESULTS
  The subsets P + O, P + R, and O + R revealed a discordance of 11%, 15.7%, and 16.6% within the classification of appendicitis, respectively. Cases designated as PA in all subsets clinically behaved as PA with a mean LOS >48 h (97, 95, and 95 h, respectively), whereas the cases designated as NPA exhibited greater variation from the expected LOS ≤48 h, with means 35, 83, and 62 h, respectively.
  
  
  CONCLUSIONS
  Variability in the classification of appendicitis between specialties suggests an error rate inherent in diagnosis. Standardizing the criteria for classification across specialties may improve the diagnostic accuracy of the type of appendicitis needed to identify best practices for optimal use of hospital resources and for meaningful clinical trials.
authors.affiliation: UT Southwestern Medical Center, Dallas, Texas.
authors.forename: Zehra
authors.initials: Z
authors.lastname: Farzal
authors.affiliation: UT Southwestern Medical Center, Dallas, Texas.
authors.forename: Zainab
authors.initials: Z
authors.lastname: Farzal
authors.affiliation: Department of Pediatric Surgery, Children's Medical Center, Dallas, Texas.
authors.forename: Nudrat
authors.initials: N
authors.lastname: Khan
authors.affiliation: Department of Pediatric Surgery, Children's Medical Center, Dallas, Texas. Electronic address: anne.fischer@beaumont.edu.
authors.forename: Anne
authors.initials: A
authors.lastname: Fischer
mesh_terms: D000293:Adolescent; D001062:Appendectomy; D001064:Appendicitis / Q000175:diagnosis* / Q000601:surgery; D002648:Child; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000706:statistics & numerical data*; D005260:Female; D013502:General Surgery; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D008297:Male; D010338:Pathology, Clinical; D011871:Radiology; D012189:Retrospective Studies; D013038:Specialization
keywords: Cost effectiveness; Discordance; Pediatric; Perforated appendicitis