What are the principles of antibiotic stewardship?

Antibiotic Stewardship: Core Principles and Implementation

Antibiotic stewardship programs must implement preauthorization and/or prospective audit and feedback as their primary intervention strategies, led by infectious disease physicians partnered with clinical pharmacists. 1

Definition and Primary Goal

Antibiotic stewardship consists of coordinated interventions designed to improve appropriate antibiotic use by promoting optimal drug selection, dosing, duration, and route of administration. 1 The fundamental objective is improving patient outcomes while simultaneously reducing adverse events (including Clostridium difficile infections), minimizing antibiotic resistance, and optimizing healthcare resource utilization. 1, 2

The "5 Ds" Framework for Appropriate Prescribing

Every antibiotic prescription must address five critical elements: 2

• Right Diagnosis: Document clinical parameters (temperature, respiratory rate, pulse, blood pressure, white blood cell count, C-reactive protein) to support bacterial infection before initiating therapy 1
• Right Drug: Select antibiotics directed against the causative pathogen based on local resistance patterns 1
• Right Dose: Optimize dosing according to pharmacokinetic/pharmacodynamic principles, patient characteristics, and infection site 3
• Right Duration: Shorten therapy duration according to current guidelines to reduce selective pressure for resistance 3
• Right De-escalation: Streamline therapy at the earliest opportunity using laboratory results 1

Essential Program Leadership and Structure

IDSA and SHEA strongly recommend that infectious disease physicians with additional stewardship training lead all antibiotic stewardship programs. 1 These physician leaders must partner with clinical pharmacists who possess infectious disease expertise. 1, 2 This leadership structure is non-negotiable for program effectiveness.

The program requires multidisciplinary collaboration including clinicians, microbiologists, and representation from all clinical areas through dedicated antimicrobial stewardship committees. 3

Core Intervention Strategies (Ranked by Evidence Strength)

Primary Strategy: Preauthorization and/or Prospective Audit with Feedback

The IDSA/SHEA guidelines provide a strong recommendation (moderate-quality evidence) for implementing preauthorization and/or prospective audit and feedback over no intervention. 1

Preauthorization requires real-time approval before administering restricted antibiotics. This approach: 1

• Reduces initiation of unnecessary/inappropriate antibiotics
• Optimizes empiric choices and influences downstream use
• Decreases antibiotic costs
• Provides direct control over antibiotic use

Critical implementation factors include ensuring the approving clinician performs direct chart review (not just verbal communication from the requesting provider, which increases inappropriate recommendations), and maintaining 24-hour availability through computerized approval systems when in-person coverage is unavailable. 1

Prospective audit and feedback (PAF) involves reviewing antibiotic prescriptions after initiation with real-time intervention to optimize therapy. This strategy: 1

• Allows more clinical data availability for recommendations, enhancing prescriber uptake
• Provides greater flexibility in timing
• Maintains prescriber autonomy
• Builds collegial relationships

PAF has demonstrated effectiveness in reducing antibiotic use by 22%, decreasing C. difficile infections, and reducing nosocomial infections from resistant Enterobacteriaceae over 7-year periods without negatively impacting mortality. 1

Secondary Strategies

Formulary restriction with limited antibiotic lists should be implemented after widespread consultation, with regular updates based on local resistance patterns. 1 However, be cautious: restrictive policies without complementary educational support can lead to unintended consequences, such as the shift from restricted cephalosporins to imipenem that resulted in a 69% increase in imipenem-resistant Pseudomonas aeruginosa. 1

Facility-specific clinical practice guidelines must be developed based on local resistance patterns, made readily accessible, created with multidisciplinary prescriber involvement, and subjected to peer review. 1, 3

Educational programs including seminars and roundtable discussions promote clinician engagement, but education alone without complementary strategies is insufficient for sustained practice change. 1, 3

Diagnostic Stewardship Integration

Implement biomarker testing and rapid pathogen identification to improve prescribing decisions. 3 Use selective blood cultures in patients with suspected infections, particularly when sepsis signs are absent. 3 Deploy rapid diagnostic testing to distinguish viral from bacterial pathogens, reducing unnecessary antibiotic use. 3

Measurement Requirements (Non-Negotiable)

Every program must measure antibiotic use using Days of Therapy (DOTs) as the preferred metric, stratified by individual antibiotic agent and normalized to patient census (DOTs per 1,000 patient-days). 4 DOTs are superior to Defined Daily Doses because they remain unaffected by dose adjustments and apply to both adult and pediatric populations. 4

Beyond volume counting, measure antibiotic appropriateness through guideline compliance and share these data with clinicians to inform prescribing practices. 4 Monitor secondary outcomes including appropriateness of therapy choice, rehospitalization rates, and time to culture review. 2, 3

Critical Implementation Pitfalls to Avoid

Do not implement education alone—this approach fails to produce sustained practice change. 3

Do not neglect local adaptation—guidelines must reflect local resistance patterns and patient populations, or program effectiveness diminishes. 3

Do not exclude frontline clinicians from program development, as this leads to program failure. 3

Do not overlook diagnostic stewardship—antimicrobial stewardship without diagnostic stewardship reduces overall program effectiveness. 3

Do not implement restrictive policies without educational support—this generates clinician resistance and potentially dangerous workarounds. 3

Special Considerations for Emergency Departments

Emergency departments require tailored approaches due to rapid patient turnover, quick decision-making requirements, and high provider variability. 1, 3 The antibiotic choice made in the ED significantly influences inpatient therapy continuation, making this a critical stewardship opportunity. 1 ED clinicians must obtain relevant cultures before antibiotic administration, as this represents the most important dose for patients with serious infections. 1

Address provider concerns about medical liability and patient satisfaction pressures through structured programs that include watchful waiting or delayed prescribing for select patients with less severe infections. 3 Implement structured culture follow-up programs for patients discharged with pending cultures to improve outcomes. 3

Extension to Long-Term Care Settings

In nursing homes and skilled nursing facilities, implement antibiotic stewardship strategies involving point-of-care providers, potentially using telemedicine consultation for infectious disease expertise when traditional physician-pharmacist teams are unavailable on-site. 1