Finally, 221 patients (30.5%) scored low probability of appendicitis. Of them, 14 patients had appendicitis (6.3%), including no cases of complicated appendicitis.
The new score was compared to the Alvarado-score and the AIR-score using ROC analysis and area under ROC curve (AUC). In this comparison, the new score had significantly better value of AUC than the others, indicating improved ability of the new score to correctly classify those with and without appendicitis (Figure 1). Using cut-off values of each scoring system chosen by authors in original articles, the diagnostic odds ratio (DOR) was clearly best for the new score (Table 3)