CRP and abscess: Optimal cutoff points for white blood cell count (WBC) (14.8 × 109/l, rounded to 15.0 × 109/l), CRP (174 mg/l, rounded to 175 mg/l), and abscess size (47 mm, rounded to 50 mm) were determined by maximum value of Youden’s index for receiver operating characteristic (ROC) curve.