title: Validating a new grading scale for emergency general surgery diseases.
abstract: BACKGROUND
  The American Association for the Surgery of Trauma (AAST) recently developed a grading scale for measuring anatomic severity of emergency general surgery (EGS) diseases. Grades were developed by expert consensus and have not been validated. The study purpose was to measure inter-rater reliability of the grading scale using colonic diverticulitis and to measure the association between disease grade and patient outcomes.
  
  
  METHODS
  All charts were reviewed and independently assigned AAST grades based on specific disease criteria. Inter-rater reliability was measured using a kappa coefficient. Multivariate regression models were used to determine the relationship between AAST disease grade and patient outcomes adjusted for age, comorbidities, and patient physiology.
  
  
  RESULTS
  Over 70% of patients demonstrated mild disease (grades I and II). No deaths were encountered. Inter-rater reliability for grade assignment was moderate (kappa coefficient, 0.43; 95% confidence interval, 0.31-0.56), with 67% concordance in grades. Compared to grade I, complications were similar in grade II but increased significantly with higher grades (grade III odds ratio [OR], 3.13 [1.32-7.41]; grade IV OR, 8.18 [2.09-32.0]; and grade V OR, 10.2 [2.68-38.90]). Compared to grade I, length of stay increased with higher grades (grade II incidence rate ratio [IRR], 1.30 [1.07-1.60]; grade III IRR, 2.4 [1.93-2.98]; grade IV IRR, 3.2 [2.27-4.60]; and grade V IRR, 2.6 [1.82-3.60]).
  
  
  CONCLUSIONS
  The EGS grading scale for diverticulitis demonstrated moderate inter-rater reliability. Higher grades were independently associated with complications and length of stay. The findings provide a positive validation that the EGS scale is easily used and effective.
authors.affiliation: Department of Surgery, University of Tennessee Health Science Center, Memphis, TN. Electronic address: ssavage1@uthsc.edu.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Savage
authors.affiliation: Institute for Health Care Research and Improvement, Baylor Scott & White Health, Dallas, Texas.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Klekar
authors.affiliation: Institute for Health Care Research and Improvement, Baylor Scott & White Health, Dallas, Texas.
authors.forename: Elisa L
authors.initials: EL
authors.lastname: Priest
authors.affiliation: Department of Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL.
authors.forename: Marie L
authors.initials: ML
authors.lastname: Crandall
authors.affiliation: Department of Surgery, University of Tennessee Health Science Center, Memphis, TN.
authors.forename: Briana C
authors.initials: BC
authors.lastname: Rodriguez
authors.affiliation: Institute for Health Care Research and Improvement, Baylor Scott & White Health, Dallas, Texas.
authors.forename: Shahid
authors.initials: S
authors.lastname: Shafi
mesh_terms: D000368:Aged; D004239:Diverticulitis, Colonic; D004632:Emergency Medical Services; D005260:Female; D013502:General Surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010865:Pilot Projects; D012720:Severity of Illness Index; D016896:Treatment Outcome
keywords: Colonic diverticulitis; Emergency general surgery; Grading scales