Correlating surgical and pathological diagnoses in pediatric appendicitis.

Background: The stratification of appendicitis into simple and complex variants has far-reaching implications. While the operative diagnosis made by the surgeon dictates clinical management, the pathologic diagnosis often differs and is frequently used for coding and reimbursement. The purpose of this study was to examine discrepancies between the operative and pathologic diagnoses with subsequent correlation to clinical outcomes.

Methods: Patients with acute appendicitis from July 2011 to July 2012 were identified. Diagnoses included simple (normal, acute, and suppurative) and complex (gangrenous and perforated). We evaluated the inter-rater reliability between pathologic and operative diagnoses in the five appendicitis categories. Clinical outcomes of deep and superficial surgical site infections were evaluated according to the pathologic and surgical diagnosis.

Results: During the study period, we identified 1166 patients with acute appendicitis. The surgeon and pathologist agreed on the specific diagnosis (acute, suppurative, gangrenous, perforated, normal) in 48% of patients (kappa 0.289, 95% CI 0.259-0.324, p=0.001). Agreement on disease severity (simple vs. complex) improved to 82%. The operative diagnosis more accurately predicted infectious complications than the pathologic diagnoses.

Conclusion: Significant discordance exists between surgical and pathologic diagnoses. While the relevance of this discordance to clinical outcomes is still not clear, a potential for incorrect hospital coding and subsequent reimbursement exists. Future quality improvement projects should focus on standardizing the surgical and pathologic diagnoses.