Evaluation of the performance of simple laboratory parameters used in the diagnosis of acute appendicitis

Background: Acute appendicitis (AA) is one of the most common emergency surgery. Aim: To evaluate the performance of laboratory parameters used in the diagnosis of AA. Subjects and Methods: There were two groups. In both groups, leukocyte (WBC), neutrophil, lymphocyte count, neutrophil/lymphocyte ratio (NLR), mean platelet volume (MPV), red cell distribution width (RDW), and platelet distribution width (PDW) values were examined in complete blood count (CBC). In addition, serum bilirubin (total bilirubin and direct bilirubin) values were examined. All laboratory parameters studied were compared to evaluate their diagnostic performance. Results: A total of 128 people were in the AA group and 122 people were in the healthy group (control). WBC count, neutrophil count, NLR, total bilirubin, direct bilirubin, and PDW values were significantly higher in the AA group than in the control group (P value <0.05). Lymphocyte counts and MPV values in the AA group were significantly lower than in the control group (P value <0.05). The sensitivity and selectivity of the WBC and neutrophil counts in AA were 95.13%, 89.34%, 94.53%, and 93.44%, respectively. The sensitivity and selectivity of the total bilirubin values were 59.38% and 73.77%, respectively. Area under the ROC curve (AUC) values within 95% confidence interval were over 0.900 for neutrophil count, WBC count, direct bilirubin, NLR, and PDW values. AUC values for total bilirubin, lymphocyte count, RDW, and MPV values were below 0.700. Conclusions: Diagnostic performances of the laboratory parameters were determined as follows: neutrophil count > WBC count > direct bilirubin = NLR = PDW > total bilirubin = lymphocyte count = RDW = MPV.