Receiver Operating Characteristic Curve and Odds Ratio Should Be Used with Caution

We read with interest the article by abu el makarem ma et al. (1) entitled, “platelet count/bipolar spleen diameter ratio for the prediction of esophageal varices: the special egyptian situation.” this study evaluated noninvasive predictors of esophageal varices in cirrhotic patients by multivariate logistic regression and receiver operating characteristic (roc) curve analysis. however, in our opinion, some aspects of the statistical analysis could be clarified. the first issue concerns the roc analysis. the full area under the roc curve (auc) is a measure of the performance of the diagnostic test because it reflects the test performance at all possible cutoff levels. the auc lies in the interval [0.5,1], and the larger area, the better performance. a perfect test has an auc of 1.0, whereas random chance gives an auc of 0.5 (2, 3). in abu el makarem ma et al.’s (1) paper, the auc for age is 0.33, which is less than 0.5. therefore, we think that something