Cost-analysis of prophylactic antibiotics in spontaneous bacterial peritonitis

Antibiotic prophylaxis has been shown to decrease the incidence of spontaneous bacterial peritonitis (SBP) in patients with cirrhosis and ascites. The aim of this study was to test whether antibiotic prophylaxis for SBP is cost-effective and to compare the costs associated with different patient groups and treatment strategies.

A cost-effectiveness analysis was performed using a Markov chain model. The costs incurred during 1-year treatment with prophylactic antibiotics vs. no prophylaxis in patients with cirrhosis and ascites were calculated. The incidence rates of primary and recurrent SBP and the mortality rate of SBP were obtained from the literature. Total direct costs of SBP treatment were determined from the wholesale price of drugs and from disbursements by the Health Care Financing Administration.

Norfloxacin prophylaxis resulted in savings between $2216 and $8545 per patient per year, depending on the patient group studied. Trimethoprim-sulfamethoxazole prophylaxis resulted in savings between $2934 and $9251 per patient per year. The groups that benefited most from prophylaxis were patients with an ascitic fluid total protein concentration of < or = 1 g/dL and those with a previous history of SBP.

The use of prophylactic antibiotics to decrease the incidence of SBP is a cost-saving strategy in patients with cirrhosis and ascites.