Validation of the American Association for the Surgery of Trauma grading system for acute appendicitis severity

Abstract

OBJECTIVE The American Association for the Surgery of Trauma (AAST) developed an anatomic grading system to assess disease severity through increasing grades of inflammation. Severity grading can then be utilized in risk-adjustment and stratification of patient outcomes for clinical benchmarking. We sought to validate the AAST appendicitis grading system by examining the ability of AAST grade to predict clinical outcomes used for clinical benchmarking. METHODS Surgical quality program data were prospectively collected on all adult patients undergoing appendectomy for acute appendicitis at our institution between December 2013 and May 2018. The AAST acute appendicitis grade from 1 to 5 was assigned for all patients undergoing open or laparoscopic appendectomy. Primary outcomes were occurrence of major complications, any complications, and index hospitalization length of stay. Multivariable models were constructed for each outcome without and with inclusion of the AAST grade as an ordinal variable. We also developed models using International Classification of Diseases, 9th or 10th Rev.—Clinical Modification codes to determine presence of perforation for comparison. RESULTS A total of 734 patients underwent appendectomy for acute appendicitis. The AAST score distribution included 561 (76%) in grade 1, 49 (6.7%) in grade 2, 79 (10.8%) in grade 3, 33 (4.5%) in grade 4, and 12 (1.6%) in grade 5. The mean age was 35.3 ± 14.7 years, 47% were female, 20% were nonwhite, and 69% had private insurance. Major complications, any complications, and hospital length of stay were all positively associated with AAST grade (p < 0.05). Risk-adjustment model fit improved after including AAST grade in the major complications, any complications, and length of stay multivariable regression models. The AAST grade was a better predictor than perforation status derived from diagnosis codes for all primary outcomes studied. CONCLUSION Increasing AAST grade is associated with higher complication rates and longer length of stay in patients with acute appendicitis. The AAST grade can be prospectively collected and improves risk-adjusted modeling of appendicitis outcomes. LEVEL OF EVIDENCE Prospective/Epidemiologic, Level III.

Where did the patients go? Changes in acute appendicitis presentation and severity of illness during the coronavirus disease 2019 pandemic: A retrospective cohort study

“…When creating the classifications of uncomplicated and complicated appendicitis, we used the validated the American Association for the Surgery of Trauma grading for acute appendicitis. 25 Extensive chart review was performed for all cases to accurately classify cases as uncomplicated or complicated. Uncomplicated appendicitis was defined as CT findings of inflammation localized to the appendix for nonoperative cases and an acutely inflamed appendix for operative cases (which could include possible gangrene and/or necrosis without evidence of perforation or abscess).…”

The Diagnostic Differentiation Challenge in Acute Appendicitis: How to Distinguish between Uncomplicated and Complicated Appendicitis in Adults

“…The American Association for the Surgery of Trauma (AAST) developed a grading system to provide a uniform method to assess disease severity, and uses clinical, radiographic, operative, and pathological criteria to assign a score of 1 to 5, where 1 is least severe and 5 is most severe [ 30 ]. This scoring system has been validated and has the potential to serve as a useful benchmarking measure by allowing the comparison of patients according to objective measures of disease severity [ 30 ].…”

The Commonest Medical, Surgical, and Oncological Causes of Acute Abdomen in Adults with COVID-19. A prospective Observational Study

“…Moderate AP is characterised by transient organ failures or local complications, while severe AP is characterised by single or multiple persistent organ failures lasting more than 48 hours (10). The severity of acute appendicitis was based on the emergency surgery grading system of the American Association for Surgery of Trauma (11). The Tokyo Guidelines severity risk scale was used to assess acute cholecystitis (12).…”