The National Healthcare Safety Network’s (NHSN’s) Standardized Antimicrobial Administration Ratio (SAAR) offers hospitals an important opportunity to improve patient safety and quality of care while achieving cost savings through an enhanced antimicrobial stewardship program (ASP). SAAR not only helps hospitals benchmark their results against their peers but more importantly, it can help hospitals optimize their ASPs by pairing SAAR data with the following:
- Analytical tools that pinpoint areas for potential improvement.
- Pharmacy-centered process improvements.
The state of antimicrobial stewardship in the US
As of 2021, 95% of U.S. hospitals have ASPs in place, largely due to the Centers for Medicaid and Medicare Services (CMS) requiring hospitals to have such programs to continue receiving CMS payments.
As of 2023, over 2,400 acute care hospitals in the U.S. have voluntarily reported to the NHSN Antimicrobial Use and Resistance (AUR) module. This represents significant progress compared to earlier years. The Centers for Medicare & Medicaid Services (CMS) announced that, starting in 2024, AUR reporting will be required under the Public Health and Clinical Data Exchange Objective.
Despite this progress, there are still implementation gaps, and the efficacy and implementation of best practices vary greatly among existing programs. Hospitals continue to prescribe unnecessary or suboptimal antibiotics about 30 percent of the time.
That percentage remains unacceptable given the costs to human health and hospital bottom lines. Understanding best practices and tailoring them to each hospital’s unique concerns is an imperative that hospitals can no longer ignore.
What is SAAR?
Hospitals that participate in the NHSN Antimicrobial Use Option receive a number, called SAAR, that is based on nationally aggregated baseline reference data. More than 2,400 participating hospitals (as of 2023) compose the reference denominator, and the NHSN adjusts each hospital’s number, a soft ratio, based on hospital size, hospital location, and the level of services provided.
A SAAR of exactly 1 indicates a hospital is using about the amount of antibiotics the NHSN would predict. A value less than 1 indicates the hospital is using less than its peers, and a value greater than 1, of course, means it is using more than its peers.
That’s a powerful starting point, but while the number provides a clear picture of utilization and patterns over time and across an entire hospital, it does not indicate the appropriateness of what each hospital is prescribing, much less what is happening in specific units or which areas are ripe for improvement.
Once they have their SAAR number, hospitals need to be able to integrate and visualize all data that contributes to the ratio, rapidly dig deeper to identify potential outliers in the topline ratio, and implement process improvements to make necessary changes to prescribing patterns.
In September 2022, the AUR module was further refined by incorporating the Targeted Assessment for Stewardship (TAS) to provide the AU-cumulative attributable difference (AU-CAD) value, which translates the SAAR target into a tangible number of antimicrobial days to reduce or add to achieve a desired SAAR. This data can support analysis of ASP-targeted interventions, like identifying the volume of work required, which can help determine staffing levels.