Elevated serum bilirubin in assessing the likelihood of perforation in acute appendicitis: a diagnostic meta-analysis.

Hyperbilirubinemia associates with perforated acute appendicitis, but the precise test characteristics have not been determined by sufficiently powered studies. A systematic literature search of reports on hyperbilirubinemia in acute appendicitis was performed. After review and quality assessment of eight studies encompassing a total of 4974 patients the sensitivity, specificity and other measures of accuracy of hyperbilirubinemia as a predictor of perforation in acute appendicitis were pooled using a random-effects model. Summary estimates for hyperbilirubinemia (cutoff 1 mg/dl) as a predictor of perforation in acute appendicitis were as follows: sensitivity, 0.49 (95% confidence interval [CI], 0.45-0.52); specificity, 0.82 (95% CI, 0.80-0.83); positive likelihood ratio, 2.51 (95% CI, 1.58-4.00); negative likelihood ratio, 0.58 (95% CI, 0.44-0.76); diagnostic odds ratio was 4.42 (95% CI, 2.21-8.83). In summary receiving operating characteristic (SROC) analysis, the area under curve was 0.73. The presence of hyperbilirubinemia does not alone distinguish a perforation in acute appendicitis. Serum bilirubin level is of some value as a predictor of appendiceal perforation. Patients with hyperbilirubinemia combined with symptoms and signs consistent with severe acute appendicitis should be considered for early appendectomy.