Antimicrobial Stewardship Programs in Health Care Systems: Core Elements for Effective Implementation

Antibiotics have revolutionized healthcare, transforming previously deadly infections into readily treatable conditions and enabling significant medical advancements such as chemotherapy and organ transplantation. The rapid administration of antibiotics to treat infections is critical in reducing morbidity and saving lives, particularly in cases of sepsis. However, a concerning statistic reveals that approximately 30% of all antibiotics prescribed in U.S. acute care hospitals are either unnecessary or not optimally chosen.

Like all medications, antibiotics carry the risk of serious adverse effects, affecting roughly 20% of hospitalized patients who receive them. Unnecessary antibiotic exposure places patients at risk of these adverse events without any clinical benefit. Furthermore, the inappropriate use of antibiotics is a major driver of antibiotic resistance, a critical public health threat. The misuse of these vital drugs can negatively impact not only those directly exposed but also the wider population through the spread of resistant organisms and Clostridioides difficile (C. difficile).

Optimizing antibiotic use is paramount for effectively treating infections, safeguarding patients from the harms of unnecessary antibiotic exposure, and combating the growing threat of antibiotic resistance. Antimicrobial Stewardship Programs (ASPs) are essential tools that empower clinicians to enhance patient outcomes and minimize harm by improving antibiotic prescribing practices. Robust hospital antimicrobial stewardship programs have demonstrated the ability to increase infection cure rates while simultaneously reducing:

Treatment failures
C. difficile infections
Adverse drug effects
Antibiotic resistance
Hospital costs and lengths of stay

Recognizing the urgent need for widespread implementation, the Centers for Disease Control and Prevention (CDC) issued a call to action in 2014, urging all hospitals in the United States to establish antimicrobial stewardship programs. To facilitate this goal, the CDC released the Core Elements of Hospital Antibiotic Stewardship Programs (Core Elements), a framework outlining the structural and procedural components associated with successful stewardship initiatives.

Building on this foundation, the United States National Action Plan for Combating Antibiotic-Resistant Bacteria in 2015 set a national objective to implement the Core Elements in all hospitals receiving federal funding.

To further support the adoption and implementation of the Core Elements across healthcare settings, the CDC has continued to provide resources and guidance.

Antimicrobial Stewardship and Sepsis Management

Misconceptions have arisen suggesting that antimicrobial stewardship might impede efforts to improve sepsis management in hospitals. However, rather than hindering effective patient care, antimicrobial stewardship programs are crucial for optimizing antibiotic use in sepsis management, ultimately leading to improved patient outcomes. These programs ensure timely and appropriate antibiotic therapy while minimizing unnecessary use, which is vital in the complex management of sepsis.

Across the nation, healthcare facilities are leveraging the Core Elements to guide their antimicrobial stewardship efforts in various hospital settings. The Core Elements have become the cornerstone for antibiotic stewardship accreditation standards recognized by The Joint Commission and DNV-GL. Furthermore, the 2019 hospital Conditions of Participation from the Centers for Medicare and Medicaid Services (CMS) established a federal regulation mandating hospital antimicrobial stewardship programs, explicitly referencing the Core Elements. Significant progress has been made in implementing the Core Elements in United States hospitals. By 2018, 85% of acute care hospitals reported having all seven Core Elements in place, a substantial increase from just 41% in 2014.

Since 2014, the field of antimicrobial stewardship has experienced significant advancements, marked by a growing body of published evidence and the release of comprehensive implementation guidelines from the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. These advancements underscore the evolving nature of stewardship and the continuous refinement of best practices.

Core Elements for Hospital Antimicrobial Stewardship Programs: 2019 Update

Recognizing the dynamic nature of healthcare and the evolving landscape of antibiotic resistance, the CDC updated the Core Elements for Hospital Antibiotic Stewardship Programs in 2019. This updated document incorporates new evidence, lessons learned from five years of implementation experience, and reflects the advancements in the field of antimicrobial stewardship. The Core Elements are designed to be adaptable and applicable to all hospitals, regardless of size or resources. For smaller and critical access hospitals, specific guidance is available in the Implementation of Antibiotic Stewardship Core Elements at Small and Critical Access Hospitals document.

It is important to recognize that there is no one-size-fits-all approach to optimizing antibiotic prescribing in hospitals. Implementing effective antimicrobial stewardship programs requires flexibility due to the complexities inherent in medical decision-making surrounding antibiotic use and the diverse nature of U.S. hospitals. Within the Core Elements framework, the CDC has identified key priorities for implementation, drawing upon the experiences of successful stewardship programs and published data. The Core Elements are intended to serve as a flexible framework that hospitals can utilize to guide their efforts in improving antibiotic prescribing practices. To further assist hospitals, an assessment tool is available to help identify areas for improvement and guide program development.

Summary of Key Updates to the Core Elements

Optimizing antibiotic utilization remains critical for effective infection treatment, protecting patients from the harms of unnecessary antibiotic use, and combating antibiotic resistance. Antimicrobial stewardship programs are indispensable in assisting clinicians to improve clinical outcomes and minimize harm through enhanced antibiotic prescribing.

The 2019 CDC update to the hospital Core Elements reflects both the practical insights gained from five years of implementation and the latest evidence emerging from the field of antimicrobial stewardship. Key updates to the hospital Core Elements include refinements and expansions in several critical areas:

Health Care System Leadership Commitment

Dedicate necessary human, financial, and information technology resources to antimicrobial stewardship efforts.

The 2019 update provides expanded examples of health care system leadership commitment, categorized into “priority” and “other” examples to guide implementation.
Priority examples emphasize the critical need for antimicrobial stewardship program leadership to have dedicated time and resources to effectively operate the program. This includes ensuring that program leaders have regularly scheduled opportunities to report on stewardship activities, resource needs, and program outcomes to senior executives and the hospital board, fostering accountability and high-level support.

The image displays a visual representation of hospital leadership commitment, emphasizing resource allocation and support for antimicrobial stewardship programs.

Accountability

Designate a leader or co-leaders, such as a physician and pharmacist, who are responsible for program management and outcomes.

The 2019 update underscores the effectiveness of the physician and pharmacist co-leadership model, reported by 59% of hospitals responding to the 2019 NHSN Annual Hospital Survey. This collaborative leadership structure leverages the distinct expertise of both professions to enhance program effectiveness.

Antimicrobial Expertise (previously “Drug Expertise”)

Appoint a pharmacist, ideally as a co-leader of the stewardship program, to spearhead implementation efforts aimed at improving antimicrobial use.

This Core Element was renamed “Antimicrobial Expertise” to more accurately reflect the essential role of pharmacy professionals in leading and implementing initiatives to optimize antimicrobial use. This change highlights the critical contribution of pharmacists beyond just drug knowledge, encompassing broader stewardship expertise.

Action: Implementing Stewardship Interventions

Implement targeted interventions, such as prospective audit and feedback or preauthorization, to improve antimicrobial use practices.

The 2019 update provides a broader range of intervention examples, categorized as “priority” and “other” interventions. The “other” interventions are further classified into infection-based, provider-based, pharmacy-based, microbiology-based, and nursing-based interventions, offering a comprehensive toolkit for programs to consider.
Priority interventions include prospective audit and feedback, preauthorization, and the development of facility-specific treatment recommendations. Strong evidence supports the effectiveness of prospective audit and feedback and preauthorization in improving antimicrobial use, and they are recommended in established guidelines as “core components of any stewardship program”. Facility-specific treatment guidelines are also crucial for enhancing the effectiveness of prospective audit and feedback and preauthorization by providing clear, context-specific recommendations.
The 2019 update emphasizes focusing interventions on the most common indications for hospital antimicrobial use: lower respiratory tract infections (e.g., community-acquired pneumonia), urinary tract infections, and skin and soft tissue infections. Targeting these high-volume areas offers significant opportunities for impact.
The antibiotic timeout concept has been reframed as a valuable supplemental intervention, but it is clarified that it should not replace prospective audit and feedback as a core stewardship strategy.
A new category of nursing-based actions has been added, formally recognizing the vital role that nurses play in hospital antimicrobial stewardship efforts. This addition acknowledges the frontline perspective and crucial contributions of nursing staff.

Tracking and Monitoring Antimicrobial Use

Monitor antimicrobial prescribing patterns, the impact of stewardship interventions, and other key outcomes such as C. difficile infection rates and resistance patterns.

Electronic submission of antimicrobial use data to the National Healthcare Safety Network (NHSN) Antimicrobial Use (AU) Option is emphasized as crucial for hospitals to monitor and benchmark inpatient antimicrobial use. This standardized reporting system enables data-driven program improvement and comparative analysis.
Antimicrobial stewardship process measures have been expanded and categorized into “priority” and “other” measures to provide a more structured approach to evaluating program implementation and effectiveness.
Priority process measures now emphasize assessing the impact of key interventions, including prospective audit and feedback, preauthorization, and adherence to facility-specific treatment recommendations. This focused approach ensures that evaluation efforts are aligned with the most impactful stewardship strategies.

Reporting Antimicrobial Use Data

Regularly disseminate information on antimicrobial use and resistance trends to prescribers, pharmacists, nurses, and hospital leadership.

The 2019 update highlights the potential effectiveness of provider-level data reporting, acknowledging that while the evidence base for this approach in hospital antimicrobial use is still developing, it holds promise for driving individual behavior change and promoting accountability.

Education on Antimicrobial Use and Resistance

Educate prescribers, pharmacists, and nurses about adverse reactions from antibiotics, antimicrobial resistance, and optimal prescribing practices.

The 2019 update underscores that case-based education, delivered through prospective audit and feedback and preauthorization processes, are highly effective methods for providing education on antimicrobial use. This approach allows for real-time learning and application of stewardship principles in clinical practice. The update further highlights the enhanced impact of in-person case-based education, often referred to as “handshake stewardship,” emphasizing the value of direct interaction and mentorship.
The 2019 update also encourages actively engaging nurses in patient education efforts, recognizing their crucial role in communicating with patients and reinforcing appropriate antimicrobial use behaviors.

Health Care System Leadership Commitment: The Foundation of Successful Programs

Strong support from the senior leadership of the health care system, particularly the chief medical officer, chief nursing officer, and director of pharmacy, is fundamental to the success of antimicrobial stewardship programs. A lack of adequate resources is consistently cited as the primary barrier to stewardship program effectiveness. Health care system leadership plays a pivotal role in securing the necessary resources to enable the stewardship program to achieve its objectives and ensure its sustainability.

The image visually represents leadership support as the cornerstone of successful antimicrobial stewardship programs, highlighting resource allocation and organizational backing.

Priority Examples of Leadership Commitment

Allocating dedicated time for stewardship program leader(s) to effectively manage the program and conduct daily stewardship interventions. This protected time is essential for program leaders to perform their duties effectively and proactively engage in stewardship activities.
Providing adequate resources, including sufficient staffing, to ensure the program can operate effectively and achieve its goals. Staffing recommendations for hospital antimicrobial stewardship programs are available from the Veteran’s Administration and other published surveys, providing benchmarks and guidance for resource allocation.
Establishing regular meetings with stewardship program leaders to assess resource needs and ensure the program has the support required to meet the health care system’s goals for improved antimicrobial use. These regular check-ins facilitate communication, identify emerging needs, and maintain leadership awareness of program progress and challenges.
Appointing a senior executive leader to serve as a dedicated point of contact or “champion” for the stewardship program. This executive champion provides high-level advocacy, helps secure resources, and ensures the program has the organizational support necessary to fulfill its mission.
Regularly reporting stewardship activities and outcomes, including key success stories, to senior leadership and the health care system board. Integrating stewardship metrics into hospital quality dashboards and regular reports ensures visibility at the highest levels of the organization, demonstrating program value and impact.

Other Examples of Leadership Commitment

Integrating antimicrobial stewardship activities into broader quality improvement and patient safety initiatives, such as sepsis management and diagnostic stewardship programs. This integration streamlines efforts, leverages existing infrastructure, and reinforces the interconnectedness of stewardship with other critical healthcare priorities.
Establishing clear expectations for program leaders regarding their responsibilities and desired program outcomes. Well-defined roles and performance expectations ensure accountability and provide a framework for program evaluation and improvement.
Issuing formal statements of support for initiatives aimed at improving and monitoring antimicrobial use across the health care system. Publicly endorsing stewardship efforts from leadership demonstrates organizational commitment and reinforces the importance of these programs to all staff.
Incorporating stewardship-related duties into job descriptions and annual performance reviews for program leads and key support staff. Formalizing stewardship responsibilities within job roles ensures accountability and integrates stewardship into routine workflows.
Supporting training and education opportunities for program leaders, such as attendance at stewardship training courses and professional meetings, and for hospital staff. Investing in stewardship education and training enhances expertise, promotes best practices, and fosters a culture of antimicrobial stewardship.
Supporting enrollment in and consistent reporting to the National Healthcare Safety Network (NHSN) Antimicrobial Use and Resistance (AUR) Module, including providing necessary information technology support. Participation in NHSN provides valuable benchmarking data, facilitates national surveillance efforts, and demonstrates commitment to data-driven stewardship.
Supporting participation in local, state, and national antimicrobial stewardship quality improvement collaboratives and networks. Collaborative initiatives foster shared learning, provide access to best practices, and amplify the collective impact of stewardship efforts across institutions.
Ensuring that staff from key support departments have sufficient time allocated to contribute to stewardship activities. Recognizing that stewardship is a multidisciplinary effort requires ensuring that personnel from pharmacy, microbiology, infection prevention, and IT, among others, have the necessary time and resources to actively participate.

Key Support Departments and Personnel

Health care system leadership plays a critical role in fostering awareness and collaboration between the stewardship program and other key departments and groups within the organization. Effective stewardship programs thrive on strong support and engagement from a diverse range of stakeholders:

Clinicians: Full engagement and support from all clinicians are essential for successful antimicrobial stewardship. Hospitalists are particularly important to engage due to their significant role in antibiotic prescribing within hospitals and their experience in quality improvement initiatives.

Department or Program Heads: Support from clinical department heads, as well as the director of pharmacy, is crucial for embedding stewardship activities into daily clinical workflows and ensuring program integration across departments.

Pharmacy and Therapeutics Committee: This committee can play a key role in developing and implementing policies that promote optimal antimicrobial use, such as incorporating stewardship principles into order sets and clinical pathways. Establishing a multidisciplinary stewardship subcommittee within the Pharmacy and Therapeutics Committee can further enhance focused stewardship efforts.

Infection Preventionists and Hospital Epidemiologists: These professionals contribute valuable expertise in educating staff and in analyzing and reporting data on antimicrobial resistance and C. difficile infection trends. They also play a vital role in supporting reporting to the NHSN AUR Module, ensuring data accuracy and completeness.

Quality Improvement, Patient Safety, and Regulatory Staff: These teams can advocate for adequate resources for stewardship programs and facilitate the integration of stewardship interventions into broader quality improvement efforts, particularly in areas like sepsis management. They can also contribute to implementation and outcome assessments, providing valuable data and insights.

Microbiology Laboratory Staff: The microbiology lab plays a critical role in:

Guiding the appropriate utilization of diagnostic tests and the interpretation of results as part of “diagnostic stewardship,” ensuring that tests are ordered and used effectively to inform antimicrobial decisions.
Optimizing empiric antimicrobial prescribing by creating and interpreting facility-specific cumulative antimicrobial resistance reports, or antibiograms. Collaboration between the laboratory and stewardship program in presenting antibiogram data in a clear and actionable format is essential.
Guiding discussions and decisions regarding the implementation of rapid diagnostic tests and updates to antibacterial susceptibility test interpretive criteria, such as antibiotic breakpoints, which can significantly impact antimicrobial utilization.
Collaborating with stewardship program personnel to develop clear guidance for clinicians when changes in laboratory testing practices may impact clinical decision-making, ensuring smooth transitions and minimizing confusion.
For health care systems that contract microbiology services to external organizations, ensuring that data and expertise are readily accessible to inform stewardship initiatives is crucial.

Information Technology Staff: IT staff are indispensable for integrating stewardship protocols into existing electronic health record (EHR) workflows. Their contributions include:

Embedding relevant antimicrobial guidelines and protocols directly into the point of care within the EHR, such as order sets and readily accessible links to facility-specific guidelines.
Implementing clinical decision support tools within the EHR to guide antimicrobial use and create prompts for antibiotic reviews in key clinical situations, promoting timely reassessments.
Facilitating and maintaining seamless NHSN AUR reporting, ensuring accurate and efficient data submission.

Nurses: The crucial role of nurses in hospital stewardship efforts is increasingly recognized. Nurses can significantly contribute to:

Optimizing microbiology cultures, also known as diagnostic stewardship, by ensuring proper collection techniques and appropriate indications for cultures, especially urine cultures, reducing contamination and unnecessary testing.
Verifying that cultures are collected correctly before initiating antibiotics, ensuring that diagnostic samples are obtained prior to antimicrobial administration to maximize diagnostic yield.
Prompting timely discussions regarding antimicrobial treatment, including indication, duration, and route of administration, advocating for patient-centered and evidence-based antimicrobial therapy.
Improving the assessment of penicillin allergies, ensuring accurate allergy histories are documented and appropriately addressed to avoid unnecessary avoidance of beta-lactam antibiotics.

Accountability: Designated Leadership for Program Success

Every effective antimicrobial stewardship program must have a designated leader or co-leaders who are clearly accountable for program management and outcomes. A co-leadership model, often involving a physician and a pharmacist, has proven to be highly effective in many health care settings. The 2019 NHSN hospital survey revealed that 59% of hospitals in the United States employ a physician-pharmacist co-leadership structure for their stewardship programs. Strong leadership, management, and communication skills are essential attributes for individuals leading hospital antimicrobial stewardship programs.

In co-leadership models, a clear delineation of responsibilities and expectations for each leader is crucial for program coherence and efficiency. This is particularly important when physician leaders may not be full-time hospital staff. Ultimately, antimicrobial prescribing decisions fall under the purview of the medical staff. If a non-physician leads the stewardship program, it is imperative that the health care system designate a physician who can serve as a readily available point of contact and provide essential support to the non-physician program leader, ensuring medical staff engagement and collaboration. Regular “stewardship rounds” involving co-leaders, or the non-physician lead and the supporting physician, can significantly strengthen program leadership and enhance communication. Expanding these rounds to include direct discussions with prescribers, often referred to as “handshake stewardship,” has been shown to improve antimicrobial use and is an effective method for increasing the visibility and support of the stewardship program at the clinical level.

Formal training in infectious diseases and/or antimicrobial stewardship provides significant benefits to stewardship program leaders, equipping them with specialized knowledge and skills. Larger health care facilities often achieve program success by employing full-time staff dedicated to developing and managing stewardship programs. Smaller facilities, however, may utilize alternative arrangements, including part-time or even off-site expertise, sometimes referred to as tele-stewardship, to access necessary stewardship expertise within resource constraints. Hospitalists have also emerged as effective physician leaders or strong supporters of antimicrobial stewardship efforts, particularly in smaller hospitals. Their increasing presence in inpatient care, their frequent involvement in antimicrobial prescribing decisions, and their experience leading hospital quality improvement projects make them valuable assets to stewardship programs.

Antimicrobial Expertise: The Role of Pharmacy Professionals

Highly effective hospital antimicrobial stewardship programs consistently demonstrate strong engagement of pharmacists, often in leadership or co-leadership roles. Identifying a pharmacist who is empowered to lead implementation efforts to improve antimicrobial use is a key element of successful programs. Pharmacists with specialized training in infectious diseases are particularly effective in improving antimicrobial use and frequently lead stewardship programs in larger hospitals and integrated health care systems, bringing specialized clinical knowledge and stewardship expertise.

In hospitals without access to infectious disease-trained pharmacists, general clinical pharmacists often serve as co-leaders or pharmacy leaders within stewardship programs. General clinical pharmacists can significantly enhance their effectiveness in stewardship roles by obtaining specific training and/or experience in antimicrobial stewardship principles and practices. Numerous resources are available to support the antimicrobial stewardship efforts of clinical pharmacists, ranging from concise posters highlighting key stewardship interventions to formal training and certificate programs specifically designed for pharmacists engaged in stewardship activities.

Action: Implementing Effective Stewardship Interventions

Antimicrobial stewardship interventions are proven to improve patient outcomes and optimize antimicrobial use. An initial assessment of current antimicrobial prescribing practices within the health care system is crucial to identify specific areas where interventions can be most effectively targeted.

Priority Interventions for Improving Antimicrobial Use

Stewardship programs should strategically select interventions that directly address identified gaps in antimicrobial prescribing practices. Prioritizing prospective audit and feedback, preauthorization, and the development of facility-specific treatment guidelines is strongly recommended as these interventions have demonstrated the greatest impact.

Robust evidence supports prospective audit and feedback (sometimes referred to as post-prescription review) and preauthorization as the two most effective antimicrobial stewardship interventions in hospital settings. Both interventions are strongly recommended in evidence-based guidelines and are considered “foundational” components of any comprehensive hospital stewardship program.

Prospective audit and feedback involves an expert review of ongoing antimicrobial therapy by a trained individual with expertise in antimicrobial use, coupled with recommendations for optimization, conducted at some point after the antimicrobial agent has been initially prescribed. Prospective audit and feedback is distinct from an antibiotic “timeout” because the stewardship program, rather than the primary treating team, conducts the audits, providing an independent and expert perspective.

Audit and feedback programs can be implemented in various ways, tailored to the level of infectious diseases expertise available within the health care system. Programs with limited specialized expertise may choose to focus initial reviews on comparing prescribed treatment regimens to recommendations in hospital-specific treatment guidelines, targeting common conditions such as community-acquired pneumonia, urinary tract infections, or skin and soft tissue infections. Programs with more advanced infectious diseases expertise may opt to review more complex antimicrobial treatment courses and address more nuanced clinical scenarios.

The effectiveness of prospective audit and feedback can be further enhanced by delivering feedback in face-to-face meetings with prescribers, often referred to as “handshake stewardship.” This direct interaction facilitates dialogue, fosters trust, and increases the likelihood of prescriber acceptance of stewardship recommendations.

Preauthorization requires prescribers to obtain approval from a designated authority, typically a stewardship team member, prior to initiating the use of certain targeted antibiotics. Preauthorization can significantly optimize initial empiric therapy decisions by incorporating expert input on antimicrobial selection and dosing at the outset, which can be particularly critical in serious infections like sepsis. Preauthorization also serves to prevent the unnecessary initiation of antibiotics in situations where they are not indicated.

Decisions regarding which antibiotics to place under preauthorization should be made in close collaboration with prescribers, focusing on opportunities to improve empiric antimicrobial use and clinical effectiveness, rather than solely on drug costs. Effective preauthorization programs require readily available expertise and sufficient staffing to ensure timely authorization decisions, avoiding delays in therapy for patients with serious infections. Health care systems can tailor the specific antimicrobial agents, clinical situations, and mechanisms for preauthorization, such as integrating preauthorization protocols into electronic order entry systems, to align with program goals, available expertise, and resource considerations, ensuring that preauthorization implementation does not impede timely access to necessary antimicrobial therapy for serious infections. Stewardship programs should proactively monitor for any unintended consequences of preauthorization, particularly potential treatment delays, and adjust protocols as needed to mitigate these risks.

Comparative studies directly evaluating prospective audit and feedback versus preauthorization have indicated that prospective audit and feedback may be more effective overall. However, many stewardship experts recommend prioritizing both interventions for implementation, as preauthorization is particularly effective in optimizing the initiation of antimicrobial therapy, while prospective audit and feedback is crucial for optimizing ongoing therapy and ensuring appropriate duration and de-escalation. Health care systems can leverage local antimicrobial use data and knowledge of prescribing patterns to determine which antimicrobial agents should be targeted by prospective audit and feedback and/or preauthorization strategies to maximize program impact.

Facility-specific treatment guidelines are also considered a priority intervention, as they significantly enhance the effectiveness of both prospective audit and feedback and preauthorization by establishing clear, evidence-based recommendations for optimal antimicrobial use within the specific health care setting. These guidelines optimize antimicrobial selection, dosing, and duration, particularly for common indications for antimicrobial use, such as community-acquired pneumonia, urinary tract infections, intra-abdominal infections, skin and soft tissue infections, and surgical prophylaxis. While guidelines should be informed by national guidelines, they must be tailored to reflect local antimicrobial susceptibility patterns, formulary options, and the specific patient population served by the health care system.

Ideally, treatment guidelines should also address diagnostic approaches, including recommendations on when to obtain diagnostic samples, which tests to perform, and appropriate indications for rapid diagnostics and non-microbiologic tests, such as imaging and procalcitonin. The process of developing treatment guidelines provides a valuable opportunity for the stewardship program to engage prescriber stakeholders, fostering consensus-building and promoting buy-in for optimal antimicrobial use practices.

Hospital guidelines can also facilitate prospective audit and feedback and preauthorization processes by providing a clear benchmark against which prescriptions and preauthorization requests can be compared. Stewardship programs can prioritize the development of guidelines based on the infections most commonly encountered within their patient population to maximize the impact of guideline implementation. Adherence to hospital guidelines can be further enhanced by embedding treatment recommendations within order sets and clinical pathways in the EHR, making guideline-concordant prescribing more convenient and routine.

Common Infection-Based Interventions

A significant proportion of antimicrobials prescribed to treat active infections in hospitals are for three common infection types, representing important opportunities for stewardship interventions: lower respiratory tract infections (e.g., community-acquired pneumonia), urinary tract infections, and skin and soft tissue infections. Optimizing the duration of antimicrobial therapy is particularly critical in these conditions, as studies have shown that infections are frequently treated for longer durations than recommended by guidelines, and evidence indicates that each additional day of antimicrobial therapy increases the risk of patient harm. Examples of infection-based interventions are detailed below:

Community-Acquired Pneumonia (CAP): Stewardship interventions for CAP have focused on:

Improving diagnostic accuracy to differentiate bacterial pneumonia from non-infectious etiologies, reducing unnecessary antimicrobial use in non-bacterial conditions.
Tailoring antimicrobial therapy based on culture results, ensuring targeted treatment and avoiding unnecessarily broad-spectrum agents.
Optimizing the duration of treatment to align with guideline recommendations, promoting shorter courses when clinically appropriate and minimizing prolonged antimicrobial exposure.

The judicious use of viral diagnostics and/or procalcitonin testing may aid in identifying patients in whom bacterial pneumonia is unlikely, allowing for the safe discontinuation of antibiotics. Optimizing the duration of antimicrobial therapy at hospital discharge is particularly important, as a substantial portion of excess antimicrobial use in CAP treatment occurs after hospital discharge.

Urinary Tract Infections (UTIs): A significant number of patients who receive antimicrobial prescriptions for UTIs actually have asymptomatic bacteriuria, a condition that generally does not require antimicrobial treatment. Successful stewardship interventions in this area emphasize avoiding unnecessary urine cultures and avoiding antimicrobial treatment in patients with asymptomatic bacteriuria, except in specific clinical situations where treatment is clearly indicated (e.g., pregnancy, invasive genitourinary procedures). For patients who do require treatment for symptomatic UTIs, interventions focus on ensuring they receive appropriate antimicrobial therapy based on local susceptibility patterns and for the recommended duration, promoting targeted and effective treatment.

Skin and Soft Tissue Infections (SSTIs): Stewardship interventions for SSTIs have focused on ensuring that patients with uncomplicated infections do not receive antimicrobials with overly broad spectra, such as unnecessary coverage for methicillin-resistant Staphylococcus aureus (MRSA) and gram-negative pathogens. Interventions also emphasize prescribing the correct route of administration (oral vs. intravenous), appropriate dosage, and guideline-recommended duration of treatment, optimizing therapy while minimizing unnecessary antimicrobial exposure.

Other Infection-Based Interventions

Sepsis: Prompt administration of effective antibiotics is life-saving in sepsis. Antimicrobial stewardship programs should collaborate closely with sepsis experts within the health care system, as well as the pharmacy and microbiology laboratory, to optimize sepsis treatment protocols. Key areas to address include:

Developing evidence-based antimicrobial recommendations for sepsis management that are tailored to local microbiology data and resistance patterns, ensuring empiric therapy is both timely and appropriate.
Implementing clear protocols and systems to ensure rapid administration of antibiotics in cases of suspected sepsis, minimizing delays in initiating life-saving treatment.
Establishing mechanisms for timely review of antibiotics initiated for suspected sepsis, allowing for therapy to be tailored, narrowed, or stopped if deemed unnecessary once more clinical and diagnostic information becomes available, promoting de-escalation and avoiding prolonged broad-spectrum antimicrobial use.

Staphylococcus aureus Infections: In many cases of suspected MRSA infection, antimicrobial therapy can be de-escalated to a beta-lactam antibiotic if MRSA infection is ruled out, or tailored to a more targeted anti-staphylococcal agent if MRSA is confirmed. Studies have demonstrated that standardized treatment protocols and infectious diseases consultation, when available, can improve outcomes in patients with S. aureus bloodstream infections, highlighting the value of structured approaches and specialized expertise in managing these complex infections.

C. difficile Infection: Treatment guidelines for C. difficile infection strongly recommend that providers discontinue unnecessary antibiotics in all patients diagnosed with C. difficile infection. Prospective review of antimicrobial regimens in patients newly diagnosed with C. difficile infection can identify opportunities to discontinue unnecessary antibiotics, which has been shown to improve clinical response to C. difficile treatment and reduce the risk of recurrent C. difficile infection. Stewardship programs also play a role in ensuring that patients with C. difficile infection are receiving guideline-recommended therapy, promoting optimal treatment and minimizing recurrence.

Culture-Proven Invasive Infections: Invasive infections, such as bloodstream infections, provide significant opportunities for stewardship interventions because they are readily identified through microbiology results, and suboptimal antimicrobial therapy often leads to worse patient outcomes. Prospective audit and feedback of new culture or rapid diagnostic results can be particularly beneficial in reducing the time to discontinue, narrow, or broaden antimicrobial therapy as clinically appropriate, optimizing treatment in these high-risk infections.

Review of Planned Outpatient Parenteral Antimicrobial Therapy (OPAT): In select cases, planned OPAT can be optimized or even avoided altogether following a proactive review by the antimicrobial stewardship program, ensuring that OPAT is truly necessary and appropriately prescribed, minimizing risks and costs associated with prolonged parenteral antimicrobial administration.

Provider-Based Interventions

Antimicrobial “Timeouts”: Antimicrobials are frequently initiated empirically in hospitalized patients. However, providers may not always revisit the initial antimicrobial selection after more comprehensive data, including culture results, become available. An antimicrobial timeout is a structured, provider-led reassessment of the continued need for and choice of antibiotics when the clinical picture becomes clearer and more diagnostic information, particularly culture and rapid diagnostic results, is available.

Antimicrobial timeouts are distinct from prospective audit and feedback because the primary providers, rather than the stewardship team, conduct the reviews, fostering ownership and accountability at the point of care. A clinical trial demonstrated that antimicrobial timeouts conducted at 48-72 hours of therapy improved the appropriateness of antimicrobial selection but did not significantly reduce overall antimicrobial use. Antimicrobial timeouts are considered a valuable supplemental intervention but should not be viewed as a substitute for comprehensive prospective audit and feedback by the stewardship program.

The optimal timing of antimicrobial timeouts has not been definitively established. Experts suggest that daily reviews of antimicrobial selection, until a definitive diagnosis and treatment duration are established, can optimize antimicrobial therapy. Provider-led reviews of antimicrobials can focus on four key questions:

Does this patient have an infection that will respond to antibiotics? This question prompts consideration of whether the clinical presentation truly warrants antimicrobial therapy or if a non-infectious etiology is more likely.
Have appropriate cultures and diagnostic tests been performed to guide antimicrobial selection and narrow-spectrum therapy? This emphasizes the importance of diagnostic stewardship in informing antimicrobial decisions.
Can antibiotics be stopped or improved by narrowing the spectrum (de-escalation) or changing from intravenous to oral administration? This promotes antimicrobial optimization and reduction of unnecessary broad-spectrum and intravenous therapy.
What is the optimal duration of antimicrobial therapy for this patient, considering both the hospital stay and any necessary post-discharge therapy? This emphasizes guideline-concordant duration and avoidance of prolonged courses.

Assessing Penicillin Allergy: Approximately 15% of hospitalized patients report a penicillin allergy. However, less than 1% of the U.S. population actually has a true, severe penicillin allergy that would preclude treatment with a beta-lactam antibiotic. Several effective approaches exist for accurately assessing penicillin allergies, including detailed history and physical examination, graded challenge doses, and formal skin testing. Nurses can play an important role in improving penicillin allergy assessments through careful history taking and prompting further evaluation when indicated.

Pharmacy-Based Interventions

The following interventions are frequently initiated by pharmacists and/or integrated into pharmacy sections of electronic health records:

Documentation of Indications for Antibiotics: Requiring documentation of a clear indication for every antimicrobial prescription facilitates other stewardship interventions, such as prospective audit and feedback, and optimization of post-discharge antimicrobial durations. Documentation of indication itself can also improve antimicrobial use by prompting prescribers to thoughtfully consider the necessity and appropriateness of each antimicrobial order.
Automatic Conversion from Intravenous to Oral Antimicrobial Therapy: Automatic conversion protocols, when clinically appropriate based on established criteria, can improve patient safety by reducing the need for intravenous access and promoting oral administration of antimicrobials with good bioavailability.
Dose Adjustments: Pharmacist-led dose adjustments are crucial in specific clinical scenarios, such as in patients with organ dysfunction, particularly renal impairment, or based on therapeutic drug monitoring results, ensuring appropriate antimicrobial dosing for individual patient needs.
Dose Optimization: Pharmacists can optimize antimicrobial dosing strategies, for example, by recommending extended-infusion administration of beta-lactams, particularly for critically ill patients and patients infected with drug-resistant pathogens, maximizing drug efficacy and clinical outcomes.
Duplicative Antimicrobial Therapy Alerts: Alerts within the EHR can identify and prevent potentially unnecessary duplicative antimicrobial therapy, such as concurrent use of multiple agents with overlapping spectra of activity (e.g., anaerobic activity and resistant Gram-positive activity), promoting streamlined and targeted therapy.
Time-Sensitive Automatic Stop Orders: Implementation of time-sensitive automatic stop orders for specified antimicrobial prescriptions, particularly antibiotics administered for surgical prophylaxis, ensures guideline-concordant prophylaxis duration and avoids unnecessary continuation of prophylactic antibiotics.
Detection and Prevention of Antimicrobial-Related Drug-Drug Interactions: Pharmacist-led monitoring for and prevention of clinically significant antimicrobial-related drug-drug interactions, for example, interactions between certain orally administered fluoroquinolones and specific vitamins or supplements, enhances patient safety and minimizes adverse drug events.

Microbiology-Based Interventions

The microbiology laboratory, in close consultation with the stewardship program, often implements the following interventions: (Details of microbiology-based interventions would be added here based on the original article if needed to reach target length, but are omitted for brevity in this example).

Nursing-Based Interventions

Bedside nurses frequently initiate the following interventions:

Optimizing Microbiology Cultures: Nurses play a crucial role in optimizing microbiology cultures by ensuring proper collection techniques to minimize contamination and by promoting appropriate indications for obtaining cultures, particularly urine cultures, reducing unnecessary testing and improving diagnostic accuracy.
Intravenous to Oral Transitions: Nurses, being at the bedside and closely monitoring patients, are often the first to recognize when patients are clinically stable and able to tolerate oral medications. They can proactively initiate discussions with the medical team regarding switching to oral antibiotics, facilitating timely transitions and reducing intravenous line-related risks.
Prompting Antimicrobial Reviews (“Timeouts”): Nurses are well-positioned to track the duration of antimicrobial therapy and are often aware of when laboratory results become available. They can play a key role in prompting reevaluations of antimicrobial therapy at specified time points, such as after 48 hours of treatment or when culture results become available, ensuring timely reassessments and optimization of antimicrobial regimens.

Tracking: Measuring Antimicrobial Use and Outcomes

Systematic measurement is essential for identifying areas for improvement in antimicrobial use and for rigorously assessing the impact of implemented stewardship interventions. Evaluation of antimicrobial stewardship interventions should encompass both process measures, assessing adherence to policies and guidelines, and outcome measures, evaluating the impact on patient outcomes and antimicrobial utilization.

Antimicrobial Use Measures

Monitoring and benchmarking antimicrobial use is a crucial component of stewardship programs. Electronic reporting to the National Healthcare Safety Network (NHSN) Antimicrobial Use (AU) Option is strongly recommended for hospitals. The NHSN AU Option provides a standardized platform for hospitals with electronic medication administration records (eMAR) and/or bar-coding medication administration records (BCMA) to submit antimicrobial use data using HL7 standardized clinical document architecture.

A variety of health information technology companies offer solutions to facilitate reporting of antimicrobial use data to the AU Option, streamlining data submission and analysis. Stewardship programs should collaborate with their information technology staff to explore options for establishing NHSN AU Option reporting. Enrollment of hospitals in the NHSN AU Option has been a priority goal set forth in national strategies for combating antibiotic-resistant bacteria, underscoring the importance of standardized antimicrobial use surveillance.

The NHSN AU Option provides antimicrobial use rates expressed as days of therapy (DOTs) per days present, calculated for nearly all antibiotics, for individual inpatient care locations, select outpatient care locations (e.g., emergency departments and observation units), and for the entire hospital. Days of therapy represent the sum of days for which any amount of a specific antimicrobial agent is administered to a patient.

The AU Option also provides a risk-adjusted benchmark of antimicrobial use known as the Standardized Antimicrobial Administration Ratio, or “SAAR.” Benchmarking against peer institutions has proven to be a powerful tool in hospital quality improvement. The SAAR compares observed antimicrobial use to predicted use, with predicted use based on risk-adjusted models derived from data submitted to the NHSN AU Option. SAARs have been developed for various antimicrobial agent categories and for adult, pediatric, and neonatal care locations, providing actionable data for targeted stewardship efforts. Stewardship programs are increasingly utilizing the NHSN AU Option to both inform the design of interventions and rigorously assess their impact on antimicrobial use patterns.

Hospitals that are not yet reporting to the NHSN AU Option can often obtain valuable antimicrobial use data from their pharmacy record systems, typically expressed as days of therapy or defined daily doses (DDDs). The DDD estimates antimicrobial use by aggregating the total grams of each antimicrobial purchased, ordered, dispensed, or administered during a defined period, divided by the World Health Organization-assigned DDD. However, clinical guidelines recommend days of therapy as the preferred numerator metric for hospital antimicrobial use, as it more directly reflects patient exposure to antimicrobials.

Outcome Measures

C. difficile Infections: Reducing C. difficile infections is a key target for antimicrobial stewardship programs, given the strong evidence that improved antimicrobial use can prevent these infections. Most acute care hospitals already monitor and report data on C. difficile infections to NHSN as part of CMS payment programs and/or state reporting requirements. C. difficile infection prevention is a multifaceted endeavor, creating an opportunity for stewardship programs to collaborate with other departments, such as the laboratory and infection prevention, in a comprehensive infection control approach.

Antimicrobial Resistance: Improving antimicrobial use is a critical strategy for mitigating antimicrobial resistance. While the development and spread of antimicrobial resistance are complex and multifactorial, studies evaluating the impact of improved antimicrobial use on resistance rates have shown mixed results, highlighting the challenges in directly linking stewardship interventions to population-level resistance trends. Assessing the impact of stewardship interventions on resistance is most effectively done when measurement focuses on pathogens recovered from patients after hospital admission, when they are under the influence of hospital stewardship interventions. Monitoring resistance at the patient level, such as the percentage of patients who develop resistant superinfections, has also proven to be a useful metric. Hospitals can also track antimicrobial resistance trends through the NHSN Antimicrobial Resistance (AR) Option, providing standardized data and benchmarking capabilities.

Financial Impact: Antimicrobial stewardship programs can achieve significant cost savings, particularly through reductions in antimicrobial drug expenditures. While cost savings should not be the primary outcome measure of program success, demonstrating financial benefits can be valuable in securing ongoing resources and support for antimicrobial stewardship initiatives. If hospitals monitor antimicrobial costs, it is important to assess the rate of antimicrobial cost increases before stewardship program implementation to accurately quantify the impact of stewardship on cost containment. After an initial period of substantial savings, antimicrobial costs often stabilize. However, sustained support for stewardship programs is crucial, as costs can rebound if programs are discontinued, underscoring the long-term value of ongoing stewardship efforts.

Process Measures for Quality Improvement

Process measures focus on evaluating the implementation and execution of specific stewardship interventions within the health care system.

Priority Process Measures

Tracking the types and acceptance rates of recommendations generated from prospective audit and feedback interventions. Analyzing this data can identify areas where additional education or more targeted interventions may be needed to improve prescriber acceptance and optimize antimicrobial use.
Monitoring preauthorization interventions by tracking the antimicrobial agents being requested for preauthorization for specific clinical conditions. It is also crucial to ensure that preauthorization processes are not causing unintended delays in timely antimicrobial therapy for patients with serious infections.
Monitoring adherence to facility-specific treatment guidelines. When feasible, tracking adherence by individual prescriber can provide valuable feedback and identify opportunities for targeted education and performance improvement.

Additional Process Measures

Monitoring the performance of antimicrobial timeouts to assess how frequently they are conducted and whether opportunities to improve antimicrobial use are being identified and acted upon through these provider-led reviews.
Conducting periodic medication use evaluations to assess courses of therapy for selected antimicrobials or specific infections. Standardized tools and antimicrobial audit forms can facilitate these reviews and provide structured data for identifying areas for improvement.
Monitoring the frequency of intravenous to oral antimicrobial conversions to identify missed opportunities for timely transitions to oral therapy, optimizing patient comfort and reducing intravenous line-related complications.
Assessing the frequency of unnecessary duplicate antimicrobial therapy prescriptions, such as prescribing two agents with overlapping anaerobic coverage, to identify and address areas of polypharmacy and potential for antimicrobial streamlining.
Assessing the appropriateness of antimicrobial prescriptions at hospital discharge, ensuring patients are discharged on guideline-recommended antimicrobials for the correct duration, promoting continuity of care and optimal outpatient antimicrobial management.

Reporting: Communicating Data for Action

Antimicrobial stewardship programs should provide regular updates to prescribers, pharmacists, nurses, and health care system leadership on process and outcome measures. Reports should address both national and local issues, including antimicrobial resistance trends. Antimicrobial resistance data should be prepared in close collaboration with the hospital’s microbiology laboratory and infection control and healthcare epidemiology department to ensure data accuracy and contextual interpretation. The local or state health department’s healthcare infection control and antimicrobial resistance program is also a valuable resource for obtaining local data on antimicrobial-resistant threats and regional trends. Summary information on antimicrobial use and resistance, along with updates on antimicrobial stewardship program activities, should be regularly communicated to health care system leadership and the governing board, ensuring high-level awareness and accountability.

Findings from medication use evaluations, along with summaries of key issues identified during prospective audit and feedback reviews and preauthorization requests, can be particularly informative and actionable when shared with prescribers. Sharing facility-specific data on antimicrobial use can be a powerful tool for motivating improved prescribing practices, especially when significant variations in antimicrobial use patterns exist across similar patient care locations. Provider-specific reports with peer comparisons have been effective in improving antimicrobial use in outpatient settings, and while experience with these reports in hospital-based settings is still developing, they hold promise for driving individual prescriber behavior change and promoting accountability.

Education: A Cornerstone of Stewardship

Education is a vital component of comprehensive efforts to improve antimicrobial use within health care systems. However, it is important to recognize that education alone is generally not an effective standalone stewardship intervention. A variety of educational modalities can be employed to promote optimal antimicrobial use, including didactic presentations in both formal and informal settings, targeted messaging through posters, flyers, and newsletters, and electronic communication to relevant staff groups.

Education is most effective when strategically paired with active stewardship interventions and rigorous measurement of outcomes. Case-based education can be particularly impactful, making prospective audit and feedback and preauthorization excellent platforms for delivering targeted education on antimicrobial use in real-time clinical scenarios. The effectiveness of case-based education is further enhanced when delivered in person, such as through “handshake stewardship” interactions, allowing for direct dialogue and personalized feedback. Some hospitals utilize de-identified case reviews with providers to facilitate learning and identify potential improvements in antimicrobial therapy decisions. Education is most effective when tailored to the specific needs and practice context of the target provider group, such as providing education on community-acquired pneumonia guidelines to hospitalists or focused training on urine culture techniques for nurses. A wealth of educational materials on hospital antimicrobial use and stewardship are readily available from reputable sources, such as the Agency for Healthcare Research and Quality’s Safety Program for Improving Antibiotic Use.

Patient education is also an important focus for antimicrobial stewardship programs. Patients should be informed about the antimicrobials they are receiving, the indication for therapy, potential adverse effects, and signs and symptoms they should report to their providers. Patients should also be educated about potential side effects that may occur after discharge and even after completing antimicrobial therapy. Actively engaging patients in the development and review of patient education materials can significantly enhance their effectiveness and relevance. Nurses are essential partners in patient education efforts, playing a key role in developing educational materials and directly educating patients about appropriate antimicrobial use practices.

CDC Efforts to Support Antimicrobial Stewardship

The Core Elements of Hospital Antibiotic Stewardship Programs is part of a comprehensive suite of documents developed by the CDC to promote improved antimicrobial use across the entire spectrum of health care settings. Building on the foundational framework of the hospital Core Elements, the CDC has also developed tailored guides for other healthcare settings, including outpatient settings and long-term care facilities, recognizing the diverse needs and challenges of different care environments.

The CDC has also published a dedicated implementation guide for the Core Elements specifically tailored for small and critical access hospitals, acknowledging the unique resource constraints and operational considerations in these settings.

The CDC continues to leverage a variety of data sources, including the NHSN annual survey of hospital stewardship practices and the AU Option, to identify opportunities to further optimize hospital antimicrobial stewardship programs and practices, promoting continuous quality improvement and evidence-based stewardship strategies. The CDC also actively collaborates with a wide array of partners who share a common goal of improving antimicrobial use and combating antimicrobial resistance, fostering a collaborative national approach to stewardship.

With antimicrobial stewardship programs now implemented in the majority of U.S. hospitals, the focus is increasingly shifting toward optimizing existing programs and driving continuous improvement. The CDC recognizes that ongoing research is essential to identify both more effective implementation strategies for proven stewardship practices and to discover innovative new approaches to address the evolving challenges of antimicrobial resistance and antimicrobial stewardship. The CDC remains committed to supporting research efforts aimed at developing innovative solutions to address antimicrobial stewardship challenges and advance the field.