Antimicrobial Stewardship Programs: Effects on Clinical and Economic Outcomes and Future Directions
Evidence Summary
The evidence for inpatient ASP effectiveness is promising but mixed. Much of the evidence is low-level, based on observational studies that are retrospective in nature, and systematic reviews and meta-analyses are based on these types of studies. Studies have been conducted over a range of years, and the duration of intervention periods often vary widely between studies; it is difficult to capture and account for all of the infection, prescribing, and drug availability patterns (as well as the intervention differences or new drug approvals) throughout these time periods. To complicate the matter, both the quality of data as well as the quality of the ASPs are highly variable.
As such, the findings across pooled studies for ASPs are hard to amalgamate and draw concrete conclusions from. This difficulty is due to the inherent heterogeneity when comparing smaller individual studies in systematic reviews and meta-analyses. Currently, there are numerous ways to implement an ASP, but there is not a standardized system of specific interventions or metrics. Until we can directly compare similar ASPs and interventions among various institutions, it will be challenging to generalize positive benefits from systematic reviews and meta-analyses. Currently, the CDC is involved in a new initiative in which data from various hospitals are compiled to create a surveillance database [48]. Although this is a step in the right direction for standardized metrics for stewardship, for the current review the lack of standard metrics leads to conflicting results of heterogenic studies, making it difficult to show clear benefits in clinical outcomes.
Despite the vast array of ASPs, their differences, and a range of clinical measures—many with conflicting evidence—there is a noticeable trend toward a more prudent use of antimicrobials. Based on the review of available evidence, inpatient ASPs improve patient care and preserve an important health care resource—antibiotics. As has been presented, this is demonstrated by the alterations in consumption of these agents, has ramifications for secondary outcomes such as reduced instances of C. difficile infections, resistance, and adverse effects, and overall translates into better patient care and reduced costs. But while we can conclude that the direct interventions of stewardship in reducing and restricting antibiotic use have been effective, we cannot clearly state the overall magnitude of benefit, the effectiveness of various ASP structures and components on clinical outcomes (such as LOS, mortality, etc.), and the cost savings due to the heterogeneity of the available evidence.
Future Directions
Moving forward, the future of ASPs encompasses several potential developments. First and foremost, as technological advancements continue to develop, there is a need to integrate and utilize developments in information technology (IT). Baysari et al conducted a review on the value of utilizing IT interventions, focusing mainly on decision support (stand-alone or as a component of other hospital procedures), approval, and surveillance systems [49]. There was benefit associated with these IT interventions in terms of the improvement in the appropriate use of antimicrobials (RR 1.49, 95% CI, 1.07–2.08, P < 0.05; I2 = 93%), but there was no demonstrated benefit in terms of patient mortality or hospital LOS. Aside from this study, broad evidence is still lacking to support the use of IT systems in ASPs because meaningful comparisons amongst the interventions have not been made due to widespread variability in study design and outcome measures. However, it is generally agreed that ASPs must integrate with IT systems as the widespread use of technology within the healthcare field continues to grow. Evidence needs to be provided in the form of higher quality studies centered on similar outcomes to show appropriate approaches for ASPs to leverage IT systems. At a minimum, the integration of IT into ASPs should not hinder clinical outcomes. An important consideration is the variation in practice settings where antibiotic stewardship is to be implemented; eg, a small community hospital will be less equipped to incorporate and support technological tools compared to a large tertiary teaching hospital. Therefore, any antibiotic stewardship IT intervention must be customized to meet local needs, prescriber behaviors, minimize barriers to implementation, and utilize available resources.
Another area of focus for future ASPs is the use of rapid diagnostics. Currently, when patients present with signs and symptoms of an infection, an empiric antimicrobial regimen is started that is then de-escalated as necessary; rapid testing will help to initiate appropriate therapy more quickly and increase antimicrobial effectiveness. Rapid tests range from rapid polymerase chain reaction (PCR)-based screening [50], to Verigene gram-positive blood culture (BC-GP) tests [51], next-generation sequencing methods, and matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) [52]. Rapid diagnostic tools should be viewed as aides to assist ASPs in decreasing antibiotic consumption and improving patient outcomes; these various tools have been shown to improve clinical outcomes when integrated into ASPs, but offer little value addressing the goals of ASPs when used outside of stewardship programs and their sensitive timeframes [53].
In terms of future ASP expansion, stewardship implementation can become more unified and broad in scope. ASPs should expand to include antifungal interventions, an area which is showing progress [36]. ASPs can also be implemented in new areas throughout the hospital (eg, pediatrics and emergency room), as well as areas outside of the hospital setting, including long-term care facilities, dialysis centers, and other institutions [54–56]. A prospective randomized control study was conducted in 30 nursing homes to evaluate the use of a novel resident antimicrobial management plan (RAMP) for improved use of antimicrobials [57]. This study found that the RAMP had no associated adverse effects and suggests that ASP is an important tool in nursing homes. In addition, the general outpatient and pediatric settings show promise for ASPs [56,58,59], but more research is needed to support expansion and to identify how ASP interventions should be applied in these various practice settings. The antimicrobial stewardship interventions that will be utilized will need to be carefully delineated to consider the scale, underlying need, and potential challenges in those settings.
While the future of antibiotic stewardship is unclear, there is certainty that it will continue to develop in both scope and depth to encompass new areas of focus, new settings to improve outcomes, and employ new tools to refine approaches. An important first step for the continued development of ASPs is alignment and standardization, since without alignment it will continue to be difficult to compare outcomes. This issue is currently being addressed by a number of different organizations. With current support from the Joint Commission, the CDC, as well as the President’s Council of Advisors on Science and Technology (PCAST) [8], regulatory requirements for ASPs are well underway, and these drivers will appropriately position ASPs for further advancements. By reducing variability amongst ASPs and delineating implementation of ASPs, there can be a clear identification of both economic and clinical benefits associated with specific interventions.
Corresponding author: Luigi Brunetti, PharmD, MPH, Rutgers, The State University of New Jersey, 160 Frelinghuysen Rd., Piscataway, NJ 08854, brunetti@pharmacy.rutgers.edu.
Financial disclosures: None.
