To simplify the model, the concrete values of CRP, PCT, and WBC were transformed into categorical variables (CRP and PCT: 1 for normal, 2 for high, 3 for undetermined; WBC: 1 for low, 2 for normal, and 3 for high), and fever was also defined as 0 for “no” and 1 for “yes.” Multivariate logistic regression analysis was performed with the five variables, and all of these potential predictors have substantial value with regard to distinguishing COVID-19 from infectious acute abdomen (Table 2). This evidence concerns the gene CRP and COVID-19.