Background: The American Association for the Surgery of Trauma (AAST) established a grading system for appendicitis to allow prediction of risk and outcomes, to assist in quality improvement and resource management, and to provide a framework for research. Grading is determined in clinical, imaging, operative, and pathologic categories, but has not been completely validated. Our aim was to validate appendicitis grade with respect to duration of symptoms, operative duration, and hospital costs.

Study design: We performed a retrospective medical record review, working backward until at least 40 of each grade of appendicitis were reviewed. Patients 8 years old and younger and those treated nonoperatively were excluded. Appendicitis severity was determined using the AAST grading scale (I to V), with V being the most severe. Statistical comparisons were made between increased grade and duration of symptoms, operative duration, hospital costs, and revenue. Data were analyzed using ANOVA or chi-square tests as appropriate.

Results: A total of 1,099 appendectomies performed between August 2013 and December 2016 were analyzed. Most were low grade. Median age was 18 years old, and 44.4% were female. Patients with increasing AAST grade had a longer symptom duration (p < 0.001), longer operative duration (p < 0.001), increased direct costs (p < 0.001) in every category measured (operating room, pharmacy, imaging, lab), and contribution margin (p < 0.001).

Conclusion: The AAST appendicitis grade is a valid predictor of disease severity as defined by operative duration, hospital cost, and revenue. Duration of symptoms predicts severity. Appendicitis grade can be used in clinical care, residency training, and resource allocation.

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