ROC curve after excluding purulent complicated parapneumonic pleural effusion cases. The sensitivity and specificity of pleural fluid sTREM-1 for differentiating between nonpurulent complicated and uncomplicated parapneumonic pleural effusions at the same cutoff value (250.5 pg/mL) became 90.48% and 83.33%, respectively. The area under the ROC curve (AUC) was 0.9444.