ObjectiveTo investigate predictive value of a new blood biochemical scoring system (CPWAG scoring system) on severity and mortality of acute pancreatitis (AP).MethodsThe AP patients who met the inclusion and exclusion criteria in our hospital from January 2017 to June 2019 were collected, then were divided into severe acute pancreatitis (SAP) group and non-SAP group according to the latest Atlanta classification. The differences of clinical characteristics and related blood biochemical indicators between the SAP group and the non-SAP group were compared. Univariate logistic regression analysis was used to screen blood biochemical risk indicators related to SAP. The receiver operating characteristic (ROC) curve was used to obtain the best cut-off value corresponding to the maximum Youden index of statistical significant risk factors and was assigned as 0 or 1 point according to different situations. At the same time, the pleural effusion of the BISAP score was included and assigned as 0 (yes) or 1 (no) point, then the CPWAG score was obtained by adding the point of the above indexes.The areas under the ROC curve (AUC) of the CPWAG, BISAP, APACHEⅡ, CTSI, and Ranson scoring systems in predicting severity and death of AP patients were also compared.ResultsA total of 451 patients with AP were included in this study, including 85 patients with SAP and 366 patients with non-SAP. Compared with the non-SAP group, the etiology of AP was mainly biliary (P<0.05), with higher levels of white blood cell count (WBC), C reactive protein (CRP), procalcitonin (PCT), and glucose (P<0.05), greater red blood cell distribution width value (P<0.05), longer prothrombin time (PT) and hospital stay (P<0.05), lower albumin (ALB) and blood calcium levels (P<0.05), higher BISAP, APACHEⅡ, CTSI and Ranson points (P<0.05), and higher proportions of patients with pleural effusion, multiple organ dysfunction syndrome, and death (P<0.05) in the SAP group. The highest score of the CPWAG scoring system included CRP, PCT, WBC, ALB, glucose, blood calcium, and pleural effusion was 7. With the increase of CPWAG score, the proportion of SAP and death patients showed an increasing trend (P<0.001). The AUC of the CPWAG scoring system in predicting SAP was 0.866, which was higher than those of Ranson (AUC=0.722, Z=5.317, P<0.001), APACHEⅡ (AUC=0.706, Z=5.019, P<0.001), and CTSI (AUC=0.805, Z=1.962, P=0.005) scoring system, but which had no statistically significant difference as compared with the BISAP scoring system (AUC=0.819, Z=1.816, P=0.070). The AUC of the CPWAG scoring system in predicting death had a high ability (AUC=0.823), which had no significant differences as compared with the Ranson, APACHEⅡ, CTSI, and BISAP scoring systems (P>0.05).ConclusionThe CPWAG score is valuable in predicting the severity and mortality of AP patients, allowing accurate and early assessment of AP patients.