Hierarchical summary receiver operating characteristic plot of serum PCT level to predict bacterial peritonitis across all settings. The curve is represented by the straight line, each of the analyzed studies is represented by a fork. The point estimate to which summary sensitivity and specificity correspond is represented by the diamond shape, and the respective 95% confidence intervals are represented by the dashed line. Abbreviation: AUC, area under the curve; SENS: summary sensitivity; SPEC: summary specificity. SROC: summary receiver operating characteristic.