Evaluation of the cost-effectiveness of rifaximin-α for the management of patients with hepatic encephalopathy in the United Kingdom

Objective: Rifaximin-alpha 550 mg twice daily plus lactulose has demonstrated efficacy in reducing recurrence of episodes of overt hepatic encephalopathy (OHE) and the risk of hepatic encephalopathy (HE)-related hospitalizations compared with lactulose alone. This analysis estimated the cost effectiveness of rifaximin-alpha 550 mg twice daily plus lactulose versus lactulose alone in United Kingdom (UK) cirrhotic patients with OHE. Method: A Markov model was built to estimate the incremental cost-effectiveness ratio (ICER). The perspective was that of the UK National Health Service (NHS). Clinical data was sourced from a randomized controlled trial (RCT) and an open-label maintenance study in cirrhotic patients in remission from recurrent episodes of OHE. Health-related utility was estimated indirectly from disease-specific quality of life RCT data. Resource use data describing the impact of rifaximin-alpha on hospital admissions and length of stay for cirrhotic patients with OHE was from four single-center UK audits. Costs (2012) were derived from published sources; costs and benefits were discounted at 3.5%. The base-case time horizon was 5 years. Results: The average cost per patient was 22,971 pound in the rifaximin-alpha plus lactulose arm and 23,545 pound in the lactulose arm, a saving of 573 pound. The corresponding values for benefit were 2.35 quality adjusted life years (QALYs) and 1.83 QALYs per person, a difference of 0.52 QALYs. This translated into a dominant base-case ICER. Key parameters that impacted the ICER included number of hospital admissions and length of stay. Conclusion: Rifaximin-alpha 550 mg twice daily in patients with recurrent episodes of OHE was estimated to generate cost savings and improved clinical outcomes compared to standard care over 5 years.