Application of ROC Curve in Diagnosis of Pleural Effusion and Ascites with Multiple Parameters

Objective To apply ROC curve to investigate the value of multiple parameters in diagnosis of pleural effusion and ascites.Methods The contents of albumin,LDH,CEA and ADA were determined in 138 cases of pleural effusion or ascites and their serum.Meanwhile the albumin gradient(AG)and the respective ratio of LDH,CEA and ADA of pleural effusion or ascites to serum were calculated.ROC curve was used to analyze the clinical properties and determine the optimal limit values.Result The optimal limit values of these parameters for differentiation of malignance and non-malignance were as follows:AG≤11.0 g/L,LDH(in pleural effusion or ascites)≥185.6 U/L,LDH ratio≥0.92,CEA(in pleural effusion or ascites)≥7.0 ng/ml,CEA ratio≥1.04.The under-ROC curve areas of the above parameters were respectively 0.809,0.849,0.828.0.843 and 0.732.The optimal limit values for diagnosis of tuberculous pleural effusion or ascites were as follows:AG≤10.5 g/L,LDH(in pleural effusion or ascites)≥180.0 U/L,LDH ratio≥0.94,ADA(in pleural effusion or ascites)≥37.74 U/L,ADA ratio≥1.11.The under-ROC curve areas of these parameters were respectively 0.776,0.797,0.849,0.936 and 0.932.Conclusion As only one single parameter is inadequate,comprehensive application of multiple parameters can improve the veracity of diagnosis.ROC curve can be used to determine the optimal limit values and serve the clinic scientifically.