Aims and Indicators for AS Programs

Table of Contents

The AS team should formulate measurable and defined goals and outcomes. A critical part of testing and implementing changes is the ability to measure them. This allows the team to know whether or not the changes they make are leading to improvements.


AS has been defined as:

‘an ongoing effort by a health-care institution to optimize antimicrobial use among hospital patients in order to:
  1. improve patient outcomes
  2. ensure cost-effective therapy
  3. and reduce adverse sequelae of antimicrobial use (including antimicrobial resistance)’*

MacDougall C, Polk R. Antimicrobial stewardship programs in health care systems. Clinical Microbiology Reviews 2005;18:638–656.


AS teams should coordinate the collection and analysis of key metrics (indicators) to assess achievement of goals, including antimicrobial use, antimicrobial resistance and compliance with antimicrobial policies.

Indicators have to be "SMART":
  • Specific
  • Measurable
  • Achievable
  • Relevant
  • Time-bound

The team should plan to collect and plot key measures data over time on a run chart or control chart. A ‘balanced’ set of measures is ideal and should include:

A) outcome measureswhat is the result?. Although outcome measures are the most relevant, these might be influenced by factors other than those related to the AS program. For example:
  • Antimicrobial consumption: overall antimicrobial consumption, specific antimicrobial consumption
  • Mortality/length of hospital stay/Readmission rates in several infectious processes (e.g. Staphylococcus aureus bloodstream infection)
  • Rate of Clostridium difficult infection

B) Process measures are the steps in the process performing as planned?. These indicators do provide a closer approach to the AS Program performance and allow to better establish comparisons among centers. For example:
  • compliance with surgical antibiotic prophylaxis prescribing
  • compliance with restriction conditions
  • patients with a toxic or subtherapeutic aminoglycoside concentration whose dosage has been adjusted or reviewed prior to the next amino glycoside dose
  • patients presenting with community acquired pneumonia that are prescribed guideline concordant antimicrobial therapy
  • patients with MSSA bloodstream infection treated with oxacillin or cefazolin

C) Balancing measuresare the changes causing new "problems"?
  • surgical site infection rate
  • topical antimicrobial usage
  • ID consultation rate

During the testing and implementing process, frequent small samples are more useful than large infrequent surveys. This will allow the team to see whether changes are resulting in improvement.

Although economic outcomes are not more important than improved clinical outcomes, they are important to measure, especially at the beginning of a new program that is not yet established or funded. A recent review suggested the most likely outcomes associated with AMS programs are cost avoidance, a reduction in antimicrobial resistance rates and a decrease in CDI.

- Antimicrobial Stewardship in Australian Hospitals(2011)

- Rodriguez Bano J, et al.[Programs for optimizing the use of antibiotics (PROA) in Spanish hospitals: GEIH-SEIMC, SEFH and SEMPSPH consensus document]. Enferm Infecc Microbiol Clin. 2012 Jan.;30(1):22.e1–22.e23.(2012)[Spanish]