Transplant patients, encompassing those who undergo bone marrow transplants (BMT), allogeneic transplants, autologous transplants, and CAR-T procedures, represent a particularly vulnerable subgroup of the population because of their immunocompromised status. The medical management of these patients involves careful monitoring and appropriate utilization of antimicrobial agents to prevent potential infections and ensure optimal health outcomes.
Vizient, the nation’s largest provider-driven healthcare performance improvement company, has taken a leading role in addressing the challenges surrounding antimicrobial utilization. Providing expertise, analytics, and advisory services to more than half of the country’s acute care providers, Vizient is at the forefront of quality improvement initiatives in healthcare. One key component of Vizient’s strategy is the Antimicrobial Stewardship Committee, a team of 37 members that includes infectious disease physicians, pharmacists, and residents. The committee meets on a monthly basis to tackle ongoing stewardship challenges in antimicrobial utilization, particularly in the context of transplant patients.
There is currently a significant gap in the field of antimicrobial stewardship: the lack of multi-center studies evaluating and benchmarking antibiotic utilization metrics in the bone marrow transplant population. The NHSN AU initiative provides reporting on utilization in BMT units, yet it does not offer benchmarking or patient-level analysis. This gap spurred the formation of the Vizient BMT Antimicrobial Utilization Project.
The project’s objectives were threefold: to describe antimicrobial utilization in transplant patients (including allogeneic, autologous, and CAR-T patients), to detail utilization across nine specific antimicrobial categories, and to correlate antimicrobial utilization with rates of C.difficile and VRE infection.
The antimicrobial categories considered in the project included anti-pseudomonal beta-lactams (comprising cefepime, ceftazidime, piperacillin-tazobactam, aztreonam), carbapenems (including ertapenem, meropenem, and imipenem-cilastatin), MDRO GNR agents, fluoroquinolones (like ciprofloxacin, levofloxacin, and moxifloxacin), MRSA-active agents (such as IV vancomycin, daptomycin, linezolid, and ceftaroline), C. difficile treatments (oral vancomycin, and fidaxomicin), antibiotics with high risk for CDI (like ceftriaxone, cefepime, clindamycin, levofloxacin, and moxifloxacin), CMV-active agents (including letermovir, ganciclovir, foscarnet, and cidofovir), and antifungals (such as fluconazole, voriconazole, posaconazole, isavuconazole, micafungin, caspofungin, anidulafungin, and ampho B).
To carry out the project, the Vizient Clinical Data Base was utilized. This database includes hospitals that perform at least 50 BMT procedures. The data analyzed spanned patient encounters from 2018-2021, excluding those involving patients under 18 years of age. The measure of ‘antimicrobial days of therapy per 1,000 patient days’ was evaluated, which gave insights into the total antimicrobial utilization in transplant encounters, as well as specific utilization in the nine major categories.
The study involved 90 hospitals and 63,379 patient encounters, which could be for BMT or CAR-T procedures, or subsequent admissions. The hospitals were diverse in terms of their size, teaching status, location, and annual BMT volumes. Similarly, the patient population was diverse in terms of age, gender, race/ethnicity, payer type, presence of Elixhauser comorbidities, the incidence of complications, and mortality. Age groups ranged from 18 to 80 or older, with a larger proportion of male patients. Non-Hispanic Whites formed the majority of the cohort. The payer type was primarily commercial, followed by Medicare and Medicaid. A significant portion of the patient population had Elixhauser comorbidities, complications, and mortality rates were also recorded.
The study provided detailed data on antimicrobial utilization for select drug categories for the entire patient cohort, as well as specific subgroups of allogeneic transplant patients, autologous transplant patients, and CAR-T procedure patients. The study found significant variability in prescribing across hospitals, particularly for agents used for treatment and prevention of C. difficile, fluoroquinolones, and antifungals.
The analysis of the data also revealed a significant association between high antimicrobial utilization rates and the rate of C. difficile infection in allogeneic transplant patients. Conversely, an inverse relationship was observed between fluoroquinolone utilization and the rate of C. difficile infection in autologous transplant patients.
These findings are critical as they underscore the impact of antimicrobial stewardship on patient outcomes. High rates of antimicrobial utilization, especially of those agents associated with a high risk for C. difficile infection, can lead to increased infection rates. Conversely, careful management of fluoroquinolone utilization can potentially reduce the rate of C. difficile infection.
It’s important to note, however, that the ability to evaluate the root cause of prescribing variability was a limitation of the study, as was the lack of microbiology data in the Vizient Database. Without microbiology data, the ability to evaluate the association between prescribing and the development of infection was limited. Furthermore, antimicrobial utilization rates are likely impacted by patient and hospital characteristics that were not accounted for in the study’s demographics.
Despite these limitations, the project represents a large BMT-focused benchmarking initiative utilizing patient-level identification. The study has helped to shine a spotlight on significant variability in prescribing across hospitals, particularly for agents used for treatment and prevention of C. difficile, fluoroquinolones, and antifungals.
The results of the study underscore the need for local stewardship practices that can impact antimicrobial utilization. By understanding the patterns of antimicrobial utilization, healthcare providers can develop strategies to optimize antibiotic use, reduce the risk of infections, and improve patient outcomes.
In conclusion, the study lays the groundwork for future initiatives aimed at improving antimicrobial stewardship in the context of transplant patients. Future efforts may include further research to understand the reasons behind prescribing variability and the development of targeted interventions to optimize antimicrobial utilization.
The work conducted by the Vizient team, including Jerod Nagel, Emily Spivak, Rupali Jain, Cory Hale, Mike Postelnick, Kim Boeser, and Alyssa Harris, is invaluable in the ongoing effort to improve antimicrobial stewardship and patient outcomes in transplant patients. Their work underscores the importance of collaboration and shared expertise in tackling complex healthcare challenges.
The study conducted by Vizient and its team is a testament to the power of data-driven healthcare initiatives. By leveraging data from multiple hospitals, the study was able to provide valuable insights into antimicrobial utilization patterns among transplant patients. These insights can be used to inform strategies aimed at reducing the risk of infections and improving patient outcomes.
In the future, it is expected that such studies will continue to play a crucial role in shaping antimicrobial stewardship strategies and practices. Through data-driven insights, healthcare providers can make informed decisions about antimicrobial use, ultimately improving the quality of care provided to transplant patients.
