HAI Surveillance


  • HAI data are used for a variety of purposes, which may include satisfying reporting mandates, comparing infection rates between and within healthcare facilities, providing consumers with information, guiding policies and procedures, evaluating the effectiveness of interventions, and conducting research.
  • Surveillance data can be categorized into process measures or outcome measures:

 Process Measures

Outcome Measures

  • Measures a process that may affect/prevent an outcome
    • Less complicated
      • Does not require risk adjustment
      • Usually easier to understand
    • Target rate = 100%
    • Applies to variety of healthcare settings
    • Involves direct care providers arrowownership / accountability
    • Ex. hand hygiene, Surgical Care Improvement Project (SCIP) measures
  • Measures actual result
    • More complicated
      • Often requires risk adjustment
      • Often more difficult to understand
    • Customized goals can be set
    • May not be able to be collected in all settings
    • May not involve direct care arrow less ownership/accountability
  • Infection prevention staff follow standardized definitions to track HAIs; these are surveillance definitions and may be different than clinical definitions, which are used to guide treatment of patients.

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Data interpretation / Common HAI measures

  • Infection rate
    • Number of infections divided by the population at risk (denominator), which varies depending on the type of infection
      • Device-associated infections
        • For catheter-associated urinary tract infections (CAUTI), the population at risk is measured in catheter days
        • For central line-associated bloodstream infections (CLABSI), the population at risk is measured in central line days
        • For ventilator-associated pneumonia (VAP), the population at risk is measured in ventilator days
      • Procedure-associated infections
        • For surgical site infections (SSI), the population at risk is measured in surgical procedures
    • Rate usually expressed per 1,000 device days (if device associated) or per 100 procedures (if procedure-associated)
    • Rate may also be expressed per 100 patients/residents to get a percentage of the selected population with a given type of infection. This measure is commonly calculated in long-term care facilities.
      • Example: The percentage of residents with a urinary tract infection (UTI) is calculated by dividing the number of residents in the surveillance area who meet the criteria for a new UTI by the number of residents in the surveillance area for the same time period, and multiplying by 100.
  • Device utilization ratio
    • Number of device-associated infections (i.e. CLABSI, CAUTI, VAP) divided by the number of device days
  • Standardized infection ratio (SIR)
    • A summary measure used to track HAIs at a national, state, or local level over time. Adjusts for patients of varying risk within each facility.
    • SIR compares the observed number of HAIs reported to the predicted (determined from baseline data reported to NHSN)
      • If the SIR <1.0, fewer HAIs were observed than predicted
      • If the SIR = 1.0, the number of HAIs observed were the same as what was predicted
      • If the SIR >1.0, more HAIs were observed than predicted
    • NHSN E-news: Guide to the Standardized Infection Ratio
    • VDH webinar – SIR 101: Interpretation and Public Reporting (April 19, 2012) (presentation) (audio)
    • VDH webinar – SIR 201: Calculating the SIR, Generating Reports, and Presenting the Data (May 3, 2012) (presentation) (audio)
    • VHQC QualitySync conference breakout session – Sir, Can You Please Explain the SIR? (June 13, 2012)(presentation)

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National Healthcare Safety Network (NHSN) and surveillance tools

  • NHSN – a secure, internet-based surveillance system designed and maintained by the Centers for Disease Control and Prevention (CDC).
    • Surveillance tools for enrolled facilities (CDC) – click on your healthcare setting type to access NHSN protocols and resources specific to that setting (i.e., acute care hospital, ambulatory surgery center, inpatient rehabilitation facility, long-term acute care facility, long-term care facility, or outpatient dialysis facility).
      • Includes tools for numerous infection types (e.g., catheter-associated urinary tract infections, central line-associated bloodstream infections, multidrug-resistant organisms/Clostridium difficile, surgical site infections, ventilator-associated events) as well as healthcare personnel influenza vaccination.
    • Training (CDC)
    • VDH webinars
      • Surveillance Strategies for Success Part 1: What’s New in NHSN for 2016 (webinar) – February 2016 (slides)
      • NHSN Surveillance: What’s New for 2015 (webinar) – December 2014 (slides) (recording)
    • National and State HAI Reports – reports that include both national data and state-specific data for states mandated by state law to report HAIs.

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HAI program activities to enhance surveillance

  • Clostridium difficile infection prevention collaborative
    • Conducted in partnership with VHQC
    • Statewide project with enrolled acute care and long-term care facilities to conduct surveillance for C. difficile labID events, implement prevention strategies, and share best practices
    • Collaborative resources available by contacting the VDH HAI Program
  • Needs assessments
    • Acute care hospitals – surveyed infection preventionists (IPs), quality improvement professionals (QIs), and administrators to describe current HAI surveillance practices, infection prevention staff responsibilities and available resources, education and training needs, organizational culture, and relationships between IPs and QIs.
    • Assisted living facilities and nursing homes – surveyed the infection prevention point of contact to describe facility demographics, infection prevention-related policies and training, current HAI surveillance practices, frequency of different types of infections, education and training needs, inter-facility communication, and the facility’s relationship with the health department and the licensing agency.
  • Surgical site infection (SSI) surveillance pilot project
    • 18 hospitals voluntarily participated in this project, which involved surveillance of coronary artery bypass graft (CABG), hip replacement, or knee replacement surgeries using NHSN to evaluate the feasibility of public reporting of these infections, quantify time requirements for surveillance, and gather lessons to help prepare other facilities in the event of future reporting requirements
    • All about SSIs: Lessons learned from the SSI surveillance pilot, SSI mini grant program, and the data presentation collaborative (Powerpoint presentation)
    • Surgical site infection (SSI) surveillance pilot project, data presentation collaborative, and SSI mini-grant report
  • SSI mini-grant program
    • Conducted in collaboration with the Virginia Hospital & Healthcare Association (VHHA)
    • 22 hospitals applied for and were awarded funds to assist with implementation of the NHSN Procedure-Associated Module in preparation for reporting surgical site infections to the Centers for Medicare and Medicaid Services (CMS) in 2012
      • Funds were used for equipment and services, training and education, consultative and technical assistance, and/or administrative support
    • Surgical site infection (SSI) surveillance pilot project, data presentation collaborative, and SSI mini-grant report
  • Urinary tract infection (UTI) prevention collaborative
    • 12 nursing homes in the Eastern region piloted the collection of UTI data using a standardized form as part of the UTI prevention collaborative
    • UTI data collection forms (Fall 2011)