The diagnostic dilemma of identifying perforated appendicitis

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).

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).

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.

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.