Comparative Effectiveness of Fidaxomicin for Treatment of Clostridium Difficile Infection

Objective: To assess the differential clinical and economic value of fidaxomicin compared with metronidazole and vancomycin in the treatment of Clostridium difficile infection (CDI). Study Design: Cohort-level Markov model simulation. Methods: We defined 4 treatment paths that varied the drugs used for initial and recurrent CDI infections. A population of adult inpatients at risk of developing CDI passed through health states, including the initial CDI treatment episode, recurrent CDI treatment episodes, persistent CDI requiring retreatment, vancomycin-resistant Enterococcus (VRE) colonization, and VRE infection. Each health state was associated with risks and costs. Our primary outcome of interest was the incremental cost per recurrence avoided. Results: The fidaxomicin-based path was superior across all the clinical outcomes considered. The incremental cost per recurrence avoided was $6109 to $13,027 higher for the fidaxomicin-based path compared with all others. For fidaxomicin to be cost neutral, the cost per recurrence would need to be between $25,000 and $48,000 depending on the comparator treatment. Conclusions: A treatment path beginning with fidaxomicin produced superior clinical outcomes but higher costs relative to 3 other treatment paths. However, fidaxomicin would be cost neutral or cost saving for patient subgroups with higher recurrence costs. Our simulations provide guidance for decision makers to optimize use of this novel and effective treatment, while also controlling costs.