Key Performance Indicators in Antimicrobial Stewardship Programs

In Antimicrobial Stewardship (AMS), data is King. Key Performance Indicators (KPIs)are essential for assessing the effectiveness of AMS programs and ensuring progress toward optimal antibiotic use and reduced antimicrobial resistance. These KPIs can be divided into several categories:

1. Antimicrobial Usage Metrics

• Defined Daily Dose (DDD) per 1,000 patient days: World Health Organization defines it as the assumed average maintenance dose per day for a drug used for its main indication in adult. DDD are often standardized to 1000 patient days (DDD/1000 patient days) to allow comparison between hospitals or services of different sizes. This tracks the quantity of antibiotics prescribed relative to patient volume. See Guidelines for ATC Classification, here.
• Days of Therapy (DOT) per 1,000 patient days: This is the number of days that a patient receives an antimicrobial agent (regardless of dose). 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. DOT is often standardized to 1000 patient days (DOT/1000 patient days) to allow comparison between hospitals or services of different sizes. This measures the duration of antibiotic use per patient to assess prescribing patterns.
• Percentage of restricted antimicrobials usage: The restriction of certain antimicrobials is a crucial component of the Antimicrobial Stewardship Policies(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.
• Appropriateness of antimicrobial therapy: Evaluates whether initial therapy aligns with guidelines or culture results. Aligns the following aspects: Diagnosis, Microbiological (MCS) results, Antimicrobial choice, Dosage, Duration and Patient factors e.g Allergies

2. Patient Outcomes

• Clostridioides difficile infections (CDI) rate per 1,000 patient days: Number of patients newly diagnosed with institution acquired CDI, divided by the number of inpatient days in that time period, multiplied by 1,000. May also be expressed as the number of new CDI cases per 1000 patient admissions. This tracks reductions in CDI rates as an indicator of better antimicrobial use.
• Hospital length of stay (LOS): Measures the impact of AMS on overall patient recovery and efficiency.
• Readmission rates related to infections: Readmission rates due to infections are a critical metric in evaluating the success of antimicrobial stewardship programs (ASPs). Tracks the recurrence of infection due to improper antibiotic usage or resistance.

3. Resistance Patterns

• Antimicrobial resistance rates: Monitors changes in the prevalence of resistant organisms over time.
• 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.

4. Process and Program Metrics

• Auditing compliance with AMS guidelines: Evaluates adherence to institutional policies and best practices.
• Rate of AMS team interventions accepted: The rate of AMS team interventions accepted is a vital performance indicator that reflects the influence and success of stewardship efforts within a healthcare setting. This metric tracks how often clinicians adopt recommendations from the AMS team, providing insight into the collaboration between prescribers and stewardship professionals and the overall effectiveness of AMS strategiesTracks how often clinicians accept recommendations from AMS teams.

5. Time to appropriate therapy:

This measures the speed of transitioning from empiric to targeted therapymeasures the duration between the initiation of empiric therapy (broad-spectrum antibiotics) and the transition to more targeted therapy, based on microbiological culture results and clinical assessment. This also factors in cases of de-escalation or discontinuation of therapy. The faster this transition occurs, the more effectively AMS teams can reduce unnecessary antimicrobial use and improve patient outcomes.

Key performance indicators (KPIs) in AMS programs provide a balanced approach to measuring the impact of AMS programs, combining clinical outcomes, process improvements, and economic benefits. By monitoing and evaluating these indicators, AMS teams can identify areas for improvement, drive meaningful change, and contribute to the global fight against AMR.

References:

1. Antimicrobial Stewardship Programs in Healthcare Facilities in Low, Middle Income Countries.
2. Antimicrobial Stewardship Programs (ASPs) Metrics Examples in Ontario, Canada
3. Practical Booklet Guide to Antimicrobial Stewardship in Hospitals : Biomerieux
4. Impact of antibiotic restriction on broad spectrum antibiotic usage in the ICU of a developing country.