Cost-Effectiveness Comparison of Fidaxomicin and Vancomycin for Treatment of Clostridium difficile Infection: A Markov Model Based on Data from a South West Balkan Country in Socioeconomic Transition ☆

Background: Recent studies have shown that fidaxomicin, a novel antibiotic, can reduce the rate of complications and mortality in patients with colitis induced by Clostridium difficile. Introduction of fidaxomicin in clinical practice is limited by its high costs. Objectives: The purpose of this study was to estimate the cost effectiveness of using fidaxomicin versus vancomycin in patients with colitis induced by C. difficile who did not respond to oral metronidazole. Methods: We constructed a Markov model that was than simulated by Monte-Carlo simulation using 1000 virtual patients with colitis induced by C. difficile. The perspective in our model was institutional. The time horizon was 3 months. Values of transition probabilities and therapy outcomes were estimated from the available literature, the prices of health services were obtained from the Republic Institute for Health Insurance Tariff Book, and the price of fidaxomicin was derived from data gained from the drug manufacturer. Results: The total costs of treating one statistical patient for 3 months with fidaxomicin were higher (48,106.19 118.07 Republic of Serbia dinars [RSD]; 95% confidence interval 47,988.12–48,224.27) than the total costs of treating with vancomycin (25,872.85 41.44 RSD; 95% confidence interval 25,831.41–25,914.29). Our results showed that the treatment of infections induced by C. difficile with fidaxomicin correlated with a lower rate of mortality and with a smaller number of colectomies. The incremental cost-effectiveness ratio of fidaxomicin versus vancomycin for colitis induced by C. difficile per saved life was estimated at 2.97 million RSD and for one avoided colectomy at 10.07 million RSD. Conclusions: Results of our model indicate that fidaxomicin is a costeffective therapy compared with vancomycin in patients with colitis induced by C. difficile if the outcome is life-year saved. However, if the outcome is the number of avoided colectomies, then fidaxomycin is not a cost-effective option compared with vancomycin.