Objective: Spontaneous bacterial peritonitis (SBP) is a severe complication in cirrhotics with ascites. Early identification of high-risk patients is crucial for prognostic improvement. We aimed to investigate the predictive value of model for end-stage liver disease (MELD) score at admission in predicting incidence rate of SBP in cirrhotic patients with ascites, so as to evaluate its use in early diagnosis and prognosis of this complication.
Methods: A retrospective study enrolling 254 consecutive patients with cirrhosis and ascites between June 2003 and June 2006 was carried out. The data collected included the age, sex, etiology of liver disease, serum creatinine, total bilirubin, prothrombin time with international normalized ratio and ascitic fluid analysis of the patients. The patients were graded with MELD formula into 4 groups (MELD < or = 9, 10-19, 20-29, MELD > or = 30). The incidence rate of SBP was compared in the 4 groups according to the MELD score. The predictive accuracy in patients with and without SBP was evaluated with receiver operating characteristic (ROC) curve.
Results: SBP developed in 65 (26%) patients during hospitalization. The clinical characteristics were similar between the patients with and without SBP. The mean MELD score for patients with SBP was 23 and for those without was 14 (P < 0.01). Patients with 10-19 had an odds ratio of 1.44 (P > 0.05) for SBP, as compared with patients with MELD < or = 9. The frequency of spontaneous bacterial peritonitis was higher in the patients with MELD > or = 20 than those with MELD < or = 19. The incidence rate of SBP with MELD < or = 19, 20-29 and MELD > or = 30 were 12.5%, 52.38%, and 66.67% respectively. Patients with MELD > or = 30 had an odds ratio of 14 (95% CI 5.41-36.20) for SBP, as compared with patients with MELD < or = 19. Patients with 20-29 had an odds ratio of 7.7 (95% CI 4.17-14.20) for SBP, as compared with patients with MELD < or = 19. Area under curve (AUC) of MELD was 0.774 (95% CI 0.689-0.855).
Conclusion: The cirrhotic patients with complicating ascites with higher MELD score have a greater risk of SBP. High MELD score might be an useful predictor of SBP in cirrhotic patients with ascites.