Implementing an Antimicrobial Stewardship Program
- Indicators for Monitoring
Key performance indicators (KPIs) in AMS programs provide a balanced approach in measuring the impact of AMS programs, combining clinical outcomes, process improvements, and economic benefits.
These are some indicators which can provide measurable data to assess compliance, identify areas for improvement, drive meaningful change, and contribute to the global fight against AMR. Here are some key indicators that can be included in hospital guidelines for monitoring and evaluating AMS programs.
These KPIs can be divided into several categories:
1. Antimicrobial Utilization
● Defined Daily Dose (DDD) per 1,000 patient-days: Measures standardized antimicrobial consumption to assess overall usage trends to allow comparison between hospitals or services of different sizes. This tracks the quantity of antibiotics prescribed relative to patient volume.
Formula: DDD/1,000 patient-days = (Total grams of antimicrobial used / WHO-assigned DDD) / Total patient-days × 1000
● Days of Therapy (DOT) per 1,000 patient-days: Tracks how many days patients receive antibiotics, offering insight into treatment duration and allows comparison between hospitals or services of different sizes. This measures the duration of antibiotic use per patient to assess prescribing patterns.
Any dose of an antibiotic that is received during a 24- hour period represents 1 DOT. The DOT for a given patient on multiple antibiotics will be the sum of DOT for each antibiotic that the patient is receiving.
Formula: DOT/1,000 patient-days = (Total number of days antimicrobial was administered / Total patient-days) × 1000
● Percentage of patients on antibiotics: Assesses the proportion of admitted patients receiving antimicrobial treatment to assess overall usage.
Formula: Percentage = (Number of patients receiving antibiotics / Total number of admitted patients) × 100
● Percentage of restricted antimicrobials usage: The restriction of certain antimicrobials is a crucial component of the ASP designed to reduce the inappropriate and frequent use of antimicrobial agents that are prone to misuse in hospital settings. Frequently evaluating the percentage of restricted antimicrobial usage, helps to monitor adherence to ASP limiting certain high-risk antimicrobials.
Formula: Percentage = (Number of patients receiving restricted antibiotics / Total number of admitted patients) × 100
2. Appropriateness of Antimicrobial Use
● Compliance with antimicrobial guidelines (%): Indicates how often prescriptions align with institutional or national guidelines.
Formula: Compliance = (Number of prescriptions compliant with guidelines / Total prescriptions reviewed) × 100
● Documented indication for antimicrobial use (%): Measures the proportion of antimicrobial prescriptions with a clearly stated reason for use.
Formula: Percentage = (Number of prescriptions with documented indication / Total antimicrobial prescriptions) × 100
● De-escalation after culture results (%): Tracks whether antimicrobial therapy is narrowed based on microbiological findings.
Formula: De-escalation Rate = (Number of de-escalations post-culture / Eligible cases for de-escalation) × 100
3. Clinical Outcomes
● Antimicrobial resistance rate (%): Monitors the percentage of resistant bacterial isolates among all tested samples.
Formula: Resistance Rate = (Number of resistant isolates / Total isolates tested) × 100
● Susceptibility rates for key pathogens: Tracks the sensitivity of pathogens to commonly used antimicrobials. This can also be done through an Antibiogram. An antibiogram is an essential resource for institutions to track changes in antimicrobial resistance and to guide empirical antimicrobial therapy. It summarizes the susceptibility of bacterial pathogens to various antibiotics, over a specific period, providing a snapshot of local resistance patterns.
Formula: Susceptibility Rate of key pathogen to a certain antibiotic = (Number of sensitive isolates to certain antibiotic/ Total isolates tested for this antibiotic) × 100
● Clostridioides difficile infection (CDI) rate per 10,000 patient-days: Evaluates the rate of CDI, which is associated with antibiotic overuse.
Formula: CDI Rate = (Number of CDI cases / Total patient-days) × 10,000
● Clostridioides difficile infections (CDI) rate per 1,000 patient days: This tracks reductions in CDI rates as an indicator of better antimicrobial use.
Formula: (Number of patients newly diagnosed with institution acquired CDI / the number of inpatient days in that time period) × 1,000. May also be expressed as the number of new CDI cases per 1000 patient admissions.
● 30-day readmission rate due to infection (%): Assesses the percentage of patients readmitted within 30 days for infection-related issues.
Formula: Readmission Rate = (Infection-related readmissions within 30 days / Total discharges) × 100
4. Process Measures
● Percentage of prescriptions reviewed by ASP team: Indicates the ASP team’s coverage of antimicrobial prescriptions.
Formula: Review Rate = (Prescriptions reviewed by ASP / Total antimicrobial prescriptions) × 100
● Acceptance rate of ASP interventions (%): Shows the percentage of ASP recommendations accepted by prescribers.
Formula: Acceptance Rate = (ASP interventions accepted / Total interventions proposed) × 100
5. Education and Awareness
● Staff trained in ASP activities per year (%): Assesses the percentage of healthcare workers trained in stewardship practices annually.
Formula: Training Coverage = (Number of staff trained / Total target staff) × 100
● Prescribers receiving regular ASP feedback (%): Measures how many prescribers receive feedback on their prescribing habits.
Formula: Feedback Rate = (Prescribers receiving feedback / Total prescribers) × 100
6. Program Implementation and Resources
● Availability of a multidisciplinary ASP team” Tracks the existence of a core team (physician, pharmacist, microbiologist, IPC).
Formula: Indicator: Yes / No
● Frequency of ASP committee meetings: Monitors how often the ASP team meets to review activities.
Formula: Indicator: Number of meetings per month/quarter
● Availability and use of electronic decision support tools: Assesses whether prescribers have access to digital tools aiding stewardship.
Formula: Indicator: Yes / No or % of units with access