184 Cost-Effective Analysis of Prophylactic Oral Vancomycin Use to Prevent Recurrent Clostridium difficile Infections in Hospitalized Patients

Abstract

INTRODUCTION: Clostridium difficile infections (CDI) is the single largest cause of morbidity and mortality among hospital acquired infections and is characterized by frequent recurrence. In the hospital setting, CDI tends to occur in patients with predisposing risk factors such as advanced age, prolonged stay, and exposure to systemic antibiotics. Although antimicrobial agents are major risk factors for CDI, their use in patients is often necessary and inevitable. There is an emerging practice of giving prophylactic oral vancomycin as secondary prophylaxis to prevent recurrent CDI. Prior published retrospective cohort studies suggest patients on systemic antimicrobial therapy who received prophylactic oral vancomycin had significantly lower rates of recurrent CDI compared to patients who did not receive the prophylaxis. However, the cost effectiveness of oral vancomycin used as secondary prophylaxis to prevent recurrent CDI is unknown. METHODS: We programmed a Markov Chain Monte Carlo simulation analytic model using published literature and national databases. For each scenario, 500 patients were simulated. The base case was modeled as a hypothetic cohort of hospitalized patients with a history of CDI, currently receiving systemic antimicrobial therapy, who either received or did not receive secondary prophylactic oral vancomycin. Projected outcomes included cost (US dollars). 2-way sensitivity analyses were conducted. A P-value less than 0.05 was considered significant. RESULTS: Across 500 simulations, prophylactic oral vancomycin resulted in a greater cost compared to no oral vancomycin at $12,045.67, 95% CI = [11880.80–12210.53] and $8,135.48, 95% CI = [8,047.37–8,223.58], respectively (Figure 1). The difference was statistically significant (P value <1 × 10−6). The treatment arm with oral vancomycin also resulted in approximately a 2.45 increased risk of mortality compared to patients who did not receive vancomycin. CONCLUSION: Our findings suggest that prophylactic oral vancomycin may not be a cost-effective strategy in reducing the incidence of CDI recurrence and may, in fact, be associated with an increased risk of mortality in hospitalized patients receiving high dose systemic antimicrobial therapy. These findings appear to be largely driven by the risk of developing vancomycin resistant enterococcus (VRE) infections, namely VRE bacteremia which is associated with high economic burden and increased mortality.