Varier RU, et al. - Researchers investigated the cost-effectiveness of fecal microbiota transplantation (FMT) vs either vancomycin or metronidazole as therapeutic options for initial Clostridium difficile infection. A decision-analytic computer simulation was constructed using inputs from published literature to compare FMT with a 10- to 14-day course of oral metronidazole or vancomycin for initial C. difficile infection. As per analysis using baseline values, FMT was less costly and more effective than vancomycin. In addition, the investigators noted higher cost and higher efficacy with FMT vs metronidazole. As per one-way sensitivity analyses, metronidazole dominated both strategies if its probability of cure were > 90%; FMT dominated if its cost was < $584. According to probabilistic sensitivity analysis, at a willingness-to-pay threshold of $100,000/quality-adjusted life years, 55% of model iterations favored metronidazole; 38% favored FMT. As the first-line treatment for C. difficile infection, metronidazole is less costly. Although a higher efficacy of FMT and vancomycin was observed, FMT is less likely to be economically favorable, and vancomycin is unlikely to be favorable as first-line therapy when compared with FMT.