The NHSN Standardized Infection Ratio (SIR): A Guide to the SIR: Updated March 2019

Details

• Corporate Authors:
  National Center for Emerging and Zoonotic Infectious Diseases (U.S.). Division of Healthcare Quality Promotion
• Description:
  The Standardized Infection Ratio (SIR) is the primary summary measure used by the National Healthcare Safety Network (NHSN) to track healthcareassociated infections (HAIs). As NHSN grows, both in its user-base and surveillance capability, the SIR continues to evolve. Highlighting the SIR and changes resulting from an updated baseline, this document is intended to serve both as guidance for those who are new to this metric as well as a useful reference for more experienced infection prevention professionals.
  
  What is the SIR? The standardized infection ratio (SIR) is a summary measure used to track HAIs at a national, state, or local level over time. The SIR adjusts for various facility and/or patient-level factors that contribute to HAI risk within each facility. The method of calculating an SIR is similar to the method used to calculate the Standardized Mortality Ratio (SMR), a summary statistic widely used in public health to analyze mortality data. In HAI data analysis, the SIR compares the actual number of HAIs reported to the number that would be predicted, given the standard population (i.e., NHSN baseline), adjusting for several risk factors that have been found to be significantly associated with differences in infection incidence. In other words, an SIR greater than 1.0 indicates that more HAIs were observed than predicted; conversely, an SIR less than 1.0 indicates that fewer HAIs were observed than predicted. SIRs are currently calculated in NHSN for the following HAI types: central line-associated bloodstream infections (CLABSI), mucosal barrier injury laboratory-confirmed bloodstream infections (MBI-LCBI), catheter-associated urinary tract infections (CAUTI), surgical site infections (SSI), Clostridioides difficile infections (CDI), methicillin-resistant Staphylococcus aureus bloodstream infections (MRSA), and ventilator-associated events (VAE).
  
  
• Subjects:
  Cross Infection Disease Transmission, Infectious Health Care Facilities Hospitals Hospitals, Rehabilitation Risk Factors Surgical Wound Infection
• Keywords:
  Standardized Infection Ratios (SIRs)
• Series:
  Standardized Infection Ratio (SIR) Guide
• Publisher:
  Centers for Disease Control and Prevention (CDC) (U.S.)
• Document Type:
  Text
• Name as Subject:
  National Healthcare Safety Network (NHSN)
• Genre:
  Pamphlet (or booklet)
• Place as Subject:
  United States
• Rights:
  Public Domain
• CIO:
  National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)
• Division:
  DHQP - Division of Healthcare Quality Promotion
• Topic:
  Diseases & Conditions
• Location:
  North America
• Pages in Document:
  49 pdf pages
• Collection(s):
  Infectious Diseases
• Main Document Checksum:
  urn:sha-512:3ecee2c1df25a3feda138093c86356f6ef56e1a6d0bb7aba7fbc75ed7196c162eb2c65caf1ee77dea7f17911c91a716e3ebcc4c58758e31707f68ccbd24dbc27
• Download URL:
  https://stacks.cdc.gov/view/cdc/258362/cdc_258362_DS1.pdf
• File Type:
  [PDF - 1.94 MB ]