A comparison of the accuracy of Tzanakis and Alvarado Score in the diagnosis of acute appendicitis: A systematic review and meta-analysis

Background and objectives: Acute appendicitis is one of the most commonly encountered surgical emergencies on a global level. Due to the requirement of an immediate clinical diagnosis and the presence of limited resources, clinicians and diagnosticians refer to scoring systems to diagnose this condition, among which Alvarado and Tzanakis scoring systems are widely used. This meta-analysis aims to compare the diagnostic accuracy of these two systems. Methods: We searched PubMed, Google Scholar, and SCOPUS databases. All studies that reported diagnostic parameters of Alvarado and Tzanakis scores in patients with suspected acute appendicitis were selected. Diagnostic values such as sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were extracted from the selected studies and statistical analysis was performed with Meta Disc 1.4 software. Quality assessment of the selected studies was performed using the QUADAS-2 and QUADAS-C tools. Fourteen studies were included in our meta-analysis which enrolled 2235 patients. Results: The overall sensitivity of the Tzanakis score was calculated as 0.86 (95% CI; 0.84-00.87) while the specificity was 0.73 (95% CI; 0.69-0.78). In addition, the area under the curve (AUC) was 0.9261 (SE; 0.0169) and the diagnostic Odds Ratio (OR) was 22.52 (95% CI; 9.47-53.56). The pooled sensitivity of Alvarado score was 0.67 (95% CI; 0.65-0.69) and the specificity was 0.74 (95% CI; 0.69-0.79). Moreover, the area under the curve (AUC) of the Alvarado score was 0.7389 (SE; 0.0489) and the diagnostic Odds Ratio was 4.92 (95% CI; 2.48-9.75). Interpretation and conclusion: The Tzanakis scoring system has a higher sensitivity, area under the curve, and diagnostic odds ratio when compared to the Alvarado score. However, the Alvarado score has a marginally better specificity making it more reliable in excluding acute appendicitis.