Impact of a Pharmacy-Driven (1,3)-β-D-Glucan Algorithm on Micafungin Duration of Therapy in the ICU

Background: The (1,3)-β-D-glucan (BDG) test can be used as a stewardship approach to decrease antifungal overutilization, development of resistance, and excess costs. Objective: This study assessed the impact that a BDG algorithm has on micafungin duration of therapy (DOT) compared to standard of care (SOC). Methods: This retrospective, multisite, pre-post cohort study at a tertiary health system included nonneutropenic critically ill adults on empiric micafungin with risk factors for invasive candidiasis (IC). A BDG algorithm was utilized and compared to SOC for micafungin DOT. Secondary outcomes included length of stay (LOS), mortality, 30-day readmissions, cost, and BDG performance. Results: A total of 110 patients were included, with 55 patients per group. Overall, micafungin DOT was not different (94.7 [45.0-146.3] vs 95.4 [49.2-206.4] hours; P = .84) but was significantly shorter when BDG resulted within 48 hours (53.0 [46.1-98.1] vs 140.7 [72.8-226.6] hours; P = .014) or with algorithm compliance following negative results (47.6 [35.6-68.8] vs 94.7 [45.0-146.3] hours; P = .005). The test had negative and positive predictive values of 96.6% and 11.5%, respectively, with dialysis patients most likely to correlate with false positives (phi = 0.40, 95% CI: 0.15-0.60, P = .002). Patients who were immunocompromised or underwent surgery had prolonged DOT. Conclusion: A pharmacy-driven BDG algorithm did not significantly decrease micafungin DOT except with BDG results within 48 hours or with algorithm compliance following negative results. The BDG test may have less impact in immunocompromised, surgery, and dialysis patients. This highlights the need for research in antifungal stewardship to optimize patient outcomes.