Hyperbilirubinemia as a Predictor of Appendiceal Perforation: A Systematic Review and Diagnostic Test Meta-Analysis

BACKGROUND: Misdiagnosis of the severity of acute appendicitis may lead to perforation and can consequently result in increased morbidity and mortality. In this study, the role of hyperbilirubinemia as a predictor of perforation is assessed by performing a meta-analysis of diagnostic accuracy. METHODS: A systematic search of the literature published over the past 20 years was performed using the EMBASE, PubMed, Cochrane library, and Google Scholar databases. RESULTS: Low values of sensitivity, specificity, and diagnostic odds ratio (DOR) were detected: 0.21 (95% confidence interval (CI): 0.13 - 0.30, standard error (SE) = 0.43), 0.27 (95% CI: 0.15 - 0.43, SE = 0.73), and 0.10 (95% CI: 0.3 - 0.28, SE = 0.05), respectively. The positive likelihood ratio (PLR) was low (0.29 (95% CI: 0.27 - 0.91, SE = 0.76)), whereas the negative likelihood ratio (NLR) was high (2.88 (95% CI: 1.66 - 5.14, SE = 0.10)). The hierarchical summary receiver operating characteristic curve was positioned towards the lower right corner, and the area under the curve was 0.19, both indicating a low level of overall accuracy and discrimination. Compared with the PLR, the negative inverse likelihood ratio (1/LR(-)) indicated that a positive result has a greater impact on the odds of disease than does a negative result. CONCLUSIONS: Hyperbilirubinemia alone is not a reliable tool to predict perforation. Future studies should investigate whether the combined predictive values of bilirubin, C-reactive protein (CRP), and white blood cells are a more effective diagnostic tool.