Analysis of risk factors of spontaneous bacterial peritonitis in cirrhotic ascites patients and diagnostic model establishment

Objective To analyze the risk factors of spontaneous bacterial peritonitis (SBP) in patients with cirrhotic ascites, and establish a diagnostic model. Methods A total of 191 patients with cirrhotic ascites who were admitted into the Affiliated Hospital of Xuzhou Medical University from January 2014 to December 2018 were enrolled. They were divided into two groups: a SBP group (n=41) and a non-SBP group (n=150). Their following data were collected: general information, complications, clinical signs and symptoms, and laboratory indicators. Univariate analysis and logistic regression analysis were used to screen out the related risk factors of SBP in patients with cirrhotic ascites, and establish a diagnostic model. The efficacy of the diagnostic model was verified by the area under the subject operating characteristic curve (AUC). Results According to univariate analysis, abdominal pain, fever, total serum albumin, serum sodium, red blood cell count, serum-ascites albumin gradient, creatinine, white blood cell count, the percentage of neutrophils, ascites white blood cell count and ascites polymorphonuclear percentage (PMN%) were correlated with SBP in cirrhotic ascites patients (P<0.05). Multivariate analysis showed that fever (OR= 4.282, 95%CI: 1.425-12.870) and ascites PMN% (OR=1.080, 95%CI: 1.053-1.107) were significantly correlated with SBP in cirrhotic ascites patients (P=0.01, P<0.001). Based on the results of multi-factor analysis, a SBP diagnostic model for cirrhotic ascites patients was established, where AUC=0.885, with an optimal cut-off value of 0.309. Conclusions Ascites PMN% and fever are independent risk factors of SBP in cirrhotic ascites patients. The established diagnostic model has a high accuracy for predicting SBP in patients with cirrhotic ascites, which provides reference for early clinical diagnosis and treatment of SBP patients in the future.