Validation and comparison of two new scoring systems for the prediction of complicated versus uncomplicated appendicitis.

Objectives: To validate the Atema and APSI scoring systems in the diagnosis of complicated vs uncomplicated appendicitis. To compare these scoring systems with computed tomography (CT) imaging alone to establish which method provides most accurate prediction of complicated vs uncomplicated appendicitis.

Methods: This was a retrospective review of a sample of 160 patients that underwent appendicectomy and CT imaging for suspected appendicitis between 2018 and 2021 in a tertiary university teaching hospital. Each scoring system was applied to all patients and results analysed and compared with the effectiveness of CT imaging, RESULTS: 32.5% (n = 52) were found to have complicated appendicitis and 67.5% (n = 108) uncomplicated appendicitis. Application of the Atema score to our cohort of patients resulted in a sensitivity 76.9% [CI (64.2, 87.5), specificity 58.7% [CI (48.9, 68.1)], PPV 47.1% [CI (40.5, 53.8) and NPV 84.2% [CI (76.0, 89.9)]. By comparison, the APSI yielded a sensitivity 50.9% [CI (36.6, 65.4)], specificity 76.1% [CI (67.0, 87.8)], PPV 50% [CI (39.2, 60.6)] and NPV 76% [CI (71.1, 81.7)]. Radiology prediction of complicated vs uncomplicated appendicitis with CT imaging showed sensitivity 46% [CI (32.2, 60.5)], specificity 79%; [CI (69.8, 86)], PPV 51% [CI (39.6, 62.5)] and NPV 75% [CI (69.8, 79.9)].

Conclusion: By comparing the APSI and Atema et al. scoring systems with CT reporting in our hospital, it appears that the Atema may confer some benefit in stratifying patient risk of complicated versus uncomplicated appendicitis. Further larger scale prospective studies are required.