2019 National and State Healthcare-Associated Infections Progress Report

Executive Summary

The Centers for Disease Control and Prevention (CDC) is committed to protecting patients and healthcare personnel from adverse healthcare events and promoting safety, quality, and value in healthcare delivery.  Preventing healthcare-associated infections (HAIs) is a top priority for CDC and its partners in public health and healthcare. The 2019 National and State Healthcare-Associated Infections (HAI) Progress Report provides a summary of select HAIs across four healthcare settings; acute care hospitals (ACHs), critical access hospitals (CAHs), inpatient rehabilitation facilities (IRFs) and long-term acute care hospitals (LTACHs). Data from CAHs are provided in the detailed technical tables but not in the report itself. The designation of CAH is assigned by the Centers for Medicare and Medicaid Services (CMS) to hospitals that have 25 or fewer acute care inpatient beds and that maintain an annual average length of stay of 96 hours or less for acute care patients. IRFs include hospitals, or part of a hospital, that provide intensive rehabilitation services using an interdisciplinary team approach. LTACHs provide treatment for patients who are generally very sick and stay, on average, more than 25 days. To view HAI data from individual hospitals, LTACHs and IRFs, please see: CMS Hospital Compareexternal icon, LTACH Compareexternal icon, and IRF Compareexternal icon.

This report, along with the detailed technical tables, provides national- and state-level HAI incidence data for 2019. The report is designed to be accessible to many audiences and is complemented by national and individual HAI factsheets that can be downloaded from the Antibiotic Resistance & Patient Safety Portal.  For detailed methods, references, and definitions please refer to the Technical Appendix and Glossary within this report. For more information, please visit CDC’s Healthcare-Associated Infection Data Reports website.

CDC’s mission in healthcare safety includes tracking infections, responding to outbreaks, providing infection prevention expertise and guidance, implementing prevention interventions in collaboration with partners, spearheading prevention research, and serving as the nation’s gold standard microbiology laboratory for the pathogens most often implicated in HAIs. CDC’s National Healthcare Safety Network (NHSN), the nation’s most widely used HAI surveillance system, is a shared resource for HAI prevention. More than 36,000 active hospitals, nursing homes, and other healthcare facilities provide data to NHSN, which in turn is used for national- and state-level analyses, including for this HAI Report, and for targeted prevention initiatives by healthcare facilities, states, regions, quality groups, and national public health agencies, including CDC.

The 2019 National and State HAI Progress Report provides data on central line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), ventilator-associated events (VAEs), surgical site infections (SSIs), methicillin-resistant Staphylococcus aureus (MRSA) bloodstream events, and Clostridioides difficile (C. difficile) events. For each of the four healthcare settings, the report provides detailed technical tables, which include additional statistics about HAIs, reporting mandates, and data validation efforts in each state and select U.S. territories. The report includes infection-specific standardized infection ratios (SIRs), which measure progress in reducing HAIs compared to the 2015 baseline time period. The SIR is the ratio of the observed number of infections (events) to the number of predicted infections (events) for a summarized time period. The report also includes the standardized utilization ratios (SURs),  which measure device use by comparing the number of observed device days to the number of predicted device days. The SIR and SUR metrics are calculated using the 2015 national baseline and risk adjustment methodology. More information about these metrics can be found at:

NHSN’s Guide to the SIR: https://www.cdc.gov/nhsn/pdfs/ps-analysis-resources/nhsn-sir-guide.pdf pdf icon[PDF – 49 pages]

NHSN’s Guide to the SUR: https://www.cdc.gov/nhsn/pdfs/ps-analysis-resources/nhsn-sur-guide-508.pdf pdf icon[PDF – 26 pages].

This report includes national data for the following HAI and facility types:

*National SSI data includes 39 inpatient surgical procedure categories reported to NHSN.

NHSN recognizes that changes to the CMS payment policies and changes in state and local reporting mandates may impact the number and characteristics of healthcare facilities participating in NHSN.

The number of states and territories that performed better than the 2015 national baseline, by infection type:

The number of states and territories that performed worse than the 2015 national baseline, by infection type:

Each day, approximately one in 31 U.S. patients has at least one infection in association with his or her hospital care, underscoring the need for improvements in patient care practices in U.S. healthcare facilities. While much progress has been made, more needs to be done to prevent healthcare-associated infections in a variety of settings.

Full engagement between local, state and federal public health agencies and their partners in the healthcare sector through initiatives such as the prevention collaboratives is vital to sustaining and extending HAI surveillance and prevention progress. CDC will continue its prevention, tracking, lab, and applied research activities to push the country further toward the goal of eliminating HAIs.

2019 HAI Progress Report

National and State Factsheets are available via the Antibiotic Resistance & Patient Safety Portal.

DATA TABLES

• 2019 SIR Data
  • 2019 National and State HAI Progress Report SIR Data – Acute Care Hospitals excel icon[XLS – 557 KB]
  • 2019 National and State HAI Progress Report SIR Data – Critical Access Hospitals excel icon[XLS – 364 KB]
  • 2019 National and State HAI Progress Report SIR Data – Inpatient Rehabilitation Facilities excel icon[XLS – 125 KB]
  • 2019 National and State HAI Progress Report SIR Data – Long-Term Acute Care Hospital excel icon[XLS – 147 KB]
  • 2019 National HAI SIR Data – Pediatric and Oncology excel icon[XLS – 60 KB]

• 2019 SUR Data
  • 2019 National and State HAI Progress Report SUR Data – Acute Care Hospitals excel icon[XLS – 273 KB]
  • 2019 National and State HAI Progress Report SUR Data – Critical Access Hospital excel icon[XLS – 159 KB]
  • 2019 National and State HAI Progress Report SUR Data – Inpatient Rehabilitation Facilities excel icon[XLS – 90 KB]
  • 2019 National and State HAI Progress Report SUR Data – Long-Term Acute Care Hospitals excel icon[XLS – 94 KB]

Technical Appendix

The 2019 National and State Healthcare-Associated Infections Data Report presents data reported to the National Healthcare Safety Network (NHSN) (http://www.cdc.gov/nhsn/) for the calendar year 2019. The healthcare-associated infection (HAI) data were reported in response to state or federal reporting requirements (via the Centers for Medicare & Medicaid Services, CMS)^1-3, or were reported voluntarily, from healthcare facilities in all 50 states, Washington, D.C., Virgin Islands, Guam, and Puerto Rico. Data included in the annual report use standard NHSN definitions for central line-associated bloodstream infections (CLABSIs), catheter-associated urinary tract infections (CAUTIs), ventilator-associated events (VAEs), surgical site infections (SSIs), laboratory-identified (LabID) methicillin-resistant Staphylococcus aureus (MRSA) bloodstream events, and LabID Clostridioides difficile (C. difficile) events.^4-8 To account for delays in reporting, 2019 data reported to NHSN through July 1, 2020 were included.

National and state data included in this report are shown separately for acute care hospitals (ACHs), critical access hospitals (CAHs), long-term acute care hospitals (LTACHs), and inpatient rehabilitation facilities (IRFs, including CMS-certified IRF units within a hospital).

The national and state standardized infection ratios (SIRs) published in this report compare the observed number of infections reported to NHSN during 2019 to the predicted number of infections based on the 2015 national baseline and risk adjustment calculations, which applies to all HAI and facility types. The risk adjustment methodology used to produce the CLABSI, CAUTI, VAE, SSI, MRSA bacteremia, and C. difficile SIRs for all facility types are summarized in NHSN’s SIR Guide pdf icon[PDF – 49 pages] (https://www.cdc.gov/nhsn/pdfs/ps-analysis-resources/nhsn-sir-guide.pdf).⁹ SSI data were risk adjusted using a logistic regression model (CDC’s Complex Admission/Readmission model), and the device-associated and LabID event SIRs were risk adjusted using a negative binomial regression model.

This report also includes national and state standardized utilization ratios (SURs) to measure device utilization for central lines, urinary catheters, and ventilators among the four main facility types. The SUR provides a summarized risk adjusted metric which allows organizations to compare device use to a national 2015 baseline. SURs are calculated by dividing the number of observed device days by the number of predicted device days; the number of predicted device days is calculated using a logistic regression model. General information about SUR calculation can be found in NHSN’s Guide to the SUR.¹⁰ 

SIRs and SURs are calculated only when at least five healthcare facilities reported 2019 data for the specific stratum, and at least one infection or device day is predicted to occur. The state-specific SIRs/SURs were calculated for each HAI and device type, location category or surgical procedure by pooling 2019 data from all reporting facilities in the state. A complete list of risk factors used in the calculation of all SIRs and SURs can be found in the technical Data Tables associated with this report. SIRs and SURs were assessed for statistical significance using a mid-p exact test. A two-tailed p-value less than 0.05 was considered a statistically significant result.

The CLABSI, CAUTI, and VAE data include data reported from all eligible inpatient locations within healthcare facilities. SIRs and SURs are stratified by location type for critical care units (ICUs), neonatal critical care units (NICUs) (CLABSI only), and inpatient wards. For this report, “wards” included step-down units, mixed acuity units, and specialty care areas including hematology/oncology and bone marrow transplant units.

When sufficient data were available, national SSI SIRs were calculated for ACHs and CAHs for each of the 39 specific procedure categories specified by NHSN; the 10 select procedures that approximate the procedures included in the Centers for Medicare & Medicaid Services (CMS) Surgical Care Improvement Project (SCIP) are shown separately. National SIRs were stratified by adult and pediatric patients. State-level SSI SIRs were calculated for 15 select procedures types, including those within the SCIP and additional procedure categories with the highest volume of reported procedures. Due to insufficient pediatric SSI data at the state-level, only adult SSI SIRs were calculated at the state-level. Only deep incisional and organ/space SSIs, regardless of closure technique, detected during the same admission as the inpatient procedure or upon readmission to the same hospital that performed the inpatient procedure were included in the SSI SIRs; superficial incisional SSIs and those identified on post-discharge surveillance or upon readmission to another facility were excluded.

MRSA bacteremia and C. difficile LabID event SIRs included laboratory results for applicable specimens and the events are classified according to day of specimen collection: hospital-onset specimens were collected on or after day 4 of admission from any inpatient location in the facility excluding CMS-certified inpatient psychiatric (IPF) units. C. difficile LabID event surveillance also excludes events from neonatal critical care units and well-baby units. Community-onset cases are reported to NHSN and are included in the risk adjustment of the LabID event SIRs.

National SIRs and SURs were calculated for all strata that met the inclusion criteria specified for each HAI above. Each national metric was compared to the 2015 national baseline of 1 and was compared to the national metric from the prior year. Both comparisons provide information on a national level about the amount of device use and healthcare-associated infections in U.S. hospitals.

Facility-specific SIRs and SURs were calculated if the facility had at least one predicted HAI (SIR) or device day (SUR). These facility-specific SIRs and SURs were used to create percentile distributions for each infection and device type if at least 20 facilities had sufficient data to calculate an SIR or SUR. Percentile distributions among the national data are shown in increments of 5, from 5-95%; key percentiles were calculated for state-level data (10%, 25%, 50%, 75%, 90%). Additionally, the facility-specific SIRs/SURs were compared to the nominal value of 1, equal to the national baseline SIR/SUR for each infection and device type; if at least 10 facilities in each category had sufficient data to calculate the metric, the percent of facilities with an SIR/SUR significantly higher or lower than the national value was calculated both nationally and by state.

Each state’s 2019 SIR was compared against three benchmarks to assess HAI prevention progress: the current 2019 national SIR, the state’s SIR from 2018, and the 2015 national baseline (i.e., compared to a value of 1). The 2019 national SIR was re-calculated for each state-to-national comparison with that state’s data removed from the 2019 national SIR in order to ensure independence. This comparison was used to determine how the state’s SIR compared to that from the rest of the nation. A comparison between the state’s 2019 and 2018 SIRs provided information about HAIs in the state during 2019, and how this compared to the same state’s SIR from the prior year. The final comparison assesses the state’s 2019 SIR against the national 2015 baseline of 1. Together, the three benchmarks provide a complete assessment of states progress in HAI prevention.

For all comparisons, a p-value less than 0.05 was considered statistically significantly different than the hypothesized value (e.g., 1 for comparison to the 2015 baseline); while two-tailed p-values were used for these comparisons and are more conservative than one-tailed p-values, significant results were interpreted as a directional change of “increase” or “decrease” based on the actual SIR values in the comparison. The three comparisons listed above were also performed and interpreted in the same manner for state-specific SURs.

The majority of healthcare facilities in the U.S. were required to report select HAI data to NHSN in 2019 for participation in various CMS Quality Reporting Programs (QRPs).¹¹ The table below provides additional details on these requirements:

2019 Required Data Elements for Participation in CMS QRPs, by Facility Type

On March 27^th, an Extraordinary Circumstance Exception (ECE) Policypdf iconexternal icon to the CMS Quality Reporting Programs was announced and applied to 2019Q4 data due to COVID-19 pandemic response activities. Many facilities across the nation were inundated with COVID-19 cases during the 2019Q4 CMS QRP reporting deadline. To alleviate some of the burden from facilities, CMS implemented an exception policy where facilities who were unable to report 2019Q4 HAI data to NHSN due to COVID-19 response activities were not penalized. Details of the exception are provided at the ECE link above. The impact of the ECE policy on the overall 2019 data is negligible as almost all facilities had reported their 2019Q4 data.

In addition to the NHSN data used to produce the SIRs in this report, the summary data on the AR&PSP and the detailed technical tables, several external data sources were used to provide additional metrics. Each year, state health department HAI programs provide CDC with the status and specific requirements of state HAI reporting mandates to NHSN and efforts to validate 2019 HAI data. The preparation of the 2019 HAI Progress Report occurred during the COVID-19 pandemic. State health departments were heavily involved in the pandemic response activities, which spanned over the reporting preparation period. To alleviate burden of gathering data on states, CDC reused the 2018 status and specific requirements of state HAI reporting mandates and efforts to validate HAI data for the 2019 report.

An indicator for a state mandate was provided for mandates enacted by either the state health department or the state’s hospital association. HAI data validation efforts were classified into two categories for each HAI type – data checked for quality and additional in-depth data review. In the 2018 report, the following criteria were used to assign credit to states that performed data quality checks: state health department had access to 2019 NHSN data, performed regular data cleaning/quality checks on at least 6 months of 2018 data prior to June 1, 2019 and contacted hospitals if data errors, outliers, or missing information were found. A state received credit for additional in-depth data review if the state performed an audit of their hospitals’ medical or laboratory records prior to June 1, 2019, meaning the state health department reviewed hospital records to confirm proper case ascertainment and data entry into NHSN. HAI data validation efforts should be considered when evaluating an individual state’s performance. States that perform more vigorous data validation activities are more likely to find hospital records of infections, and therefore these states may have higher SIRs compared to states that do not perform validation. Not all state health departments have access to NHSN data or have access to NHSN data from every hospital included in this report. Data validation efforts were self-reported by state health departments to CDC.

References

1. Centers for Medicare and Medicaid Services. Hospital Inpatient Quality Reporting Program. Available at https://www.cms.gov/medicare/quality-initiatives-patient-assessment-instruments/hospitalqualityinits/hospitalrhqdapu.htmlexternal icon. Accessed August 17, 2020.Inpatient Rehabilitation Facilities Quality Reporting Program. Available at https://www.medicare.gov/inpatientrehabilitationfacilitycompare/external icon. Accessed August 17, 2020.
   Long-Term Acute Care Hospital Quality Reporting Program. Available at https://www.medicare.gov/longtermcarehospitalcompare/external icon. Accessed August 17, 2020.
2. Centers for Medicare and Medicaid Services. Long-Term Care Hospital Quality Reporting. Available at https://www.cms.gov/Medicare/Quality-Initiatives-Patient-Assessment-Instruments/LTCH-Quality-Reporting/external icon. Accessed August 17, 2020.
3. Centers for Medicare and Medicaid Services. Inpatient Rehabilitation Facilities (IRF) Quality Reporting Program (QRP). Available at https://www.cms.gov/Medicare/Quality-Initiatives-Patient-Assessment-Instruments/IRF-Quality-Reporting/index.htmlexternal icon. Accessed August 17, 2020.
4. Centers for Disease Control and Prevention. Acute care hospital surveillance for central line-associated bloodstream infections. http://www.cdc.gov/nhsn/acute-care-hospital/clabsi/index.html. Accessed August 17, 2020.
5. Centers for Disease Control and Prevention. Acute care hospital surveillance for catheter-associated urinary tract infections. http://www.cdc.gov/nhsn/acute-care-hospital/cauti/index.html. Accessed August 17, 2020.
6. Centers for Disease Control and Prevention. Acute care hospital surveillance for surgical site infections. http://www.cdc.gov/nhsn/acute-care-hospital/ssi/index.html. Accessed August 17, 2020.
7. Centers for Disease Control and Prevention. Acute care hospital surveillance for C. difficile, MRSA, and other drug-resistant infections. Available at http://www.cdc.gov/nhsn/acute-care-hospital/cdiff-mrsa/index.html. Accessed August 17, 2020.
8. Centers for Disease Control and Prevention. Acute care hospital surveillance for Ventilator-associated Events (VAE). Available at https://www.cdc.gov/nhsn/acute-care-hospital/vae/index.html. Accessed August 17, 2020.
9. Centers for Disease Control and Prevention. The NHSN Standardized Infection Ratio (SIR): a guide to the SIR. Available at https://www.cdc.gov/nhsn/pdfs/ps-analysis-resources/nhsn-sir-guide.pdf pdf icon[PDF – 49 pages]. Accessed August 17, 2020.
10. Centers for Disease Control and Prevention. The NHSN Standardized Utilization Ratio (SUR): a guide to the SUR. Available at https://www.cdc.gov/nhsn/pdfs/ps-analysis-resources/nhsn-sur-guide-508.pdf pdf icon[PDF – 26 pages]. Accessed August 17, 2020.
11. Healthcare Facility HAI Reporting Requirements to CMS via NHSN – Current or Proposed Requirements. National Healthcare Safety Network website. https://www.cdc.gov/nhsn/pdfs/cms/cms-reporting-requirements.pdf pdf icon[PDF – 2 pages]. Accessed August 17, 2020.
    

Acknowledgements

We thank the infection preventionists, hospital epidemiologists, and other dedicated hospital and health department staff who work to support HAI surveillance and prevention measures. This report was prepared by the CDC’s National Center for Emerging and Zoonotic Infectious Diseases, Division of Healthcare Quality Promotion staff.

Glossary

Terms and topics from CDC’s National and State Healthcare-Associated Infections Progress Report.

Click on the category to locate specific terms:
Organizations and Hospitals  §  Infections Reported  §  Prevention Collaboratives  §  Calculations

ORGANIZATIONS and HOSPITALS

Acute care hospitals (ACHs): A hospital is an institution that mainly provides diagnostic and therapeutic services to inpatients, including medical diagnosis, treatment, and care. The Centers for Medicare & Medicaid Services requires that all patients in hospitals be under the care of a physician and provided 24-hour nursing assistance.

Centers for Disease Control and Prevention (CDC): Housed within U.S. Department of Health and Human Servicesexternal icon, CDC is charged with protecting the public health of the nation by providing leadership and direction in the prevention of and control of diseases and other preventable conditions, and responding to public health emergencies. CDC works 24/7 to protect America from health, safety and security threats, both foreign and in the United States.

Emerging Infections Program (EIP): A national resource utilized for surveillance, prevention, and control of emerging infectious diseases. EIP is a network of state health departments and their collaborators in local health departments, academic institutions, other federal agencies, and public health and clinical laboratories; infection preventionists; and healthcare providers.

Hospital Compareexternal icon: A consumer-oriented website that provides information about the quality of care at over 4,000 Medicare-certified hospitals. Hospital Compare was created through the efforts of the Centers for Medicare & Medicaid Servicesexternal icon (CMS), in collaboration with organizations representing consumers, hospitals, doctors, employers, accrediting organizations, and other Federal agencies. Hospitals participating in the CMS quality reporting program submit healthcare-associated infection data to CDC’s National Healthcare Safety Network (NHSN). NHSN shares these data with CMS for public posting on Hospital Compare to help consumers make informed decisions about their health care.

Inpatient rehabilitation facilities (IRF)external icon: Hospitals, or part of a hospital that provide intensive rehabilitation services using an interdisciplinary team approach. Admission to an IRF is appropriate for patients with complex nursing, medical management, and rehabilitative needs. Data in this report are reported from free-standing IRFs and CMS-certified IRF units within other hospitals.

Long-term acute care hospital (LTACH)external icon: Acute care hospitals that provide treatment for patients who are generally very sick and stay, on average, more than 25 days. Services include comprehensive rehabilitation, respiratory therapy, head trauma treatment, and pain management. Most patients are transferred from an intensive or critical care unit.

National Healthcare Safety Network (NHSN): CDC’s NHSN is the nation’s most widely used healthcare-associated (HAI) infection tracking system. NHSN provides facilities, states, regions, and the nation with data needed to identify problem areas, measure progress of prevention efforts, and ultimately eliminate HAIs. In addition, NHSN allows healthcare facilities to track blood safety errors and important healthcare process measures such as healthcare personnel influenza vaccine status and infection control adherence rates.

INFECTIONS REPORTED

Catheter-associated urinary tract infection (CAUTI): A urinary tract infection (UTI) is an infection involving any part of the urinary system, including urethra, bladder, ureters, and kidney. When a urinary catheter is not put in correctly, not kept clean, or left in a patient for too long, germs can travel through the catheter and infect the bladder and kidneys. In this report, the CAUTI data include all infections reported to National Healthcare Safety Network from all applicable locations, including intensive care units and wards.

Central line-associated bloodstream infection (CLABSI): When a tube is placed in a large vein and not put in correctly or kept clean, it can become a way for germs to enter the body and cause deadly infections in the blood. In this report, the CLABSI data include all infections reported to National Healthcare Safety Network from all applicable locations, including intensive care units, neonatal intensive care unit, and wards.

Clostridioides difficile (C. difficile): When a person takes antibiotics, good bacteria that protect against infection are destroyed for several months. During this time, patients can get sick from C. difficile, bacteria that can cause life-threatening diarrhea. Often, C. difficile infections occur in hospitalized or recently hospitalized patients. In this report, the C. difficile data include all laboratory identified hospital-onset infections reported to National Healthcare Safety Network from all inpatient locations in the facility, except for the neonatal intensive care units and well-baby locations.

Healthcare-associated infection (HAI): Infection patients can get while receiving medical treatment in hospitals, outpatient clinics, nursing homes, and other facilities where people receive care.

• Hospital-onset LabID:  For reporting to National Healthcare Safety Network, a LabID event is considered hospital-onset if the patient begins to show infection symptoms on or after the fourth day of admission.
• Laboratory identified (LabID) Event: For reporting to National Healthcare Safety Network, an infection is considered laboratory identified when a patient sample is tested and confirmed by laboratory test only (i.e., clinical evaluation of the patient is not required).

Methicillin-resistant Staphylococcus aureus (MRSA): A type of staph bacteria that is resistant to many antibiotics. In this report, the MRSA data include all laboratory-identified hospital-onset MRSA bacteremia (bloodstream infections) reported to National Healthcare Safety Network from all inpatient locations in the facility.

Surgical site infection (SSI): When germs get into an area where surgery is or was performed, patients can get a surgical site infection. Sometimes these infections involve only the skin. Other SSIs can involve tissues under the skin, organs, or implanted material (an object or material inserted or grafted into the body, such as prosthetic joints).

PREVENTION COLLABORATIVES

Antibiotic stewardship: Coordinated efforts and programs to improve the use of antimicrobials in healthcare settings to ensure that hospitalized patients receive the right antibiotic, at the right dose, at the right time, and for the right duration.

Antibiotic resistance: Antibiotic resistance is the result of bacteria changing in ways that reduce or eliminate the effectiveness of antibiotics.

Carbapenem-resistant Enterobacterales (CRE) infections: A family of germs that is difficult to treat because they have high levels of resistance to antibiotics. CRE infections are most commonly seen in people with exposure to healthcare settings, like hospitals and long-term care facilities.

Hand hygiene: The practice of cleaning hands to prevent the spread of disease-causing germs.

Healthcare personnel influenza vaccination: Influenza, or the flu, is a mild to severe respiratory illness caused by a virus. The contagious illness can easily spread from person to person, including from healthcare workers to patients. Vaccination is the best way to prevent getting and spreading the flu.

Long-term care facilities (LTCF): Nursing homes, skilled nursing facilities, and assisted living facilities (collectively known as long-term care facilities) provide a variety of services, both medical and personal care, to people who are unable to manage independently in the community.

Multidrug-resistant organism (MDRO) infections: An infection caused by germs that are resistant to multiple classes of antimicrobials. In some cases, the germs have become so resistant that no available antibiotics are effective against them.

Prevention collaboratives: Prevention projects that consist of multiple healthcare facilities within a state or region to target an infection as a team, implement prevention strategies, share experiences between facilities, measure progress as a group, and provide feedback to clinicians and staff.

Targeted Assessment for Prevention (TAP) strategy: A quality improvement framework developed by the Centers for Disease Control and Prevention (CDC) to use data for action to prevent healthcare-associated infections (HAIs). The TAP Strategy targets healthcare facilities and specific units within facilities with a disproportionate burden of HAIs to identify and address infection prevention gaps.

Ventilator-associated events (VAE): A ventilator is a machine used to help a patient breathe by giving oxygen through a tube placed in a patient’s mouth or nose, or through a hole in the front of the neck. An infection may occur if germs enter a patient through the tube, such as pneumonia or bacterial infections in the blood.

CALCULATIONS

National baseline: Aggregated data reported to the National Healthcare Safety Network (NHSN) by all facilities during a baseline period that is used to “predict” the number of infections expected to occur in a hospital, state, or in the country.
In this report, the number of predicted infections is an estimate based on infections reported to NHSN during the 2015 national baseline for all facility types.

Standardized Infection Ratio (SIR): A summary statistic that can be used to track healthcare-associated infection (HAI) prevention progress over time; lower SIRs are better. The SIR compares the number of infections in a facility or state to the number of infections that were “predicted” to have occurred, based on previous years of reported data (see National baseline). The SIR is not calculated when the number of predicted infections is less than 1. In this report, the SIRs compare the observed number of infections reported to the National Healthcare Safety Network (NHSN) during the surveillance period to the predicted number of infections based on the 2015 referent period, adjusting for key risk factors.

• Risk adjustment: A process used to level the playing field by adjusting for the differences in risk. When the data are risk-adjusted, it makes it possible to fairly compare hospital performance. In this report, the SIRs are adjusted for risk factors that may impact the number of infections reported by a hospital, such as type of patient care location, bed size of the hospital, patient age, and other factors.
• National SIR: A summary statistic calculated from all reported HAIs that occurred in the country during the surveillance period. It was calculated as the total number of observed infections in the country, divided by the total number of predicted infections in the country during the surveillance period.
• State SIR: A summary statistic calculated from all reported HAIs that occurred in an individual state during the surveillance period. It was calculated as the total number of observed infections from all hospitals in the state, divided by the total number of predicted infections in the state during the surveillance period.

Standardized Utilization Ratio (SUR): A summary statistic that can be used to track device utilization over time; lower SURs are better. The SUR compares the number of device days (central lines, urinary catheters, ventilators) in a facility or state to the number of device days that were “predicted” to have occurred, based on previous years of reported data (see National baseline). The SUR is not calculated when the number of predicted device days is less than 1. In this report, the SURs compare the observed number of device days reported to the National Healthcare Safety Network (NHSN) during the surveillance period to the predicted number of device days based on the 2015 referent period, adjusting for key risk factors.

State mandate (for data reporting): A state legislative or regulatory requirement (enacted by the state’s government or promulgated by a state agency) requiring hospitals (and other healthcare facilities) in the state’s jurisdiction to report healthcare-associated infections to the National Healthcare Safety Network.

Validation: Double-checking, or confirming, healthcare-associated infection (HAI) data reported to the National Healthcare Safety Network (NHSN). This generally involves an assessment to ensure all relevant infections were captured in the system. It may also involve checking the accuracy, or quality, of the submitted data. Currently, state health departments may use different methods to validate the HAI data that hospitals submit to NHSN. For example, some states only validate data from one facility while other states validate more widely. Validation efforts should be considered when evaluating an individual state’s performance. States that validate data or use advanced tools to detect HAIs may find and report more infections than states that do not validate.
In this report, state validation efforts are specified and classified into two categories for each HAI type: data checked for quality and additional in-depth data review.

“Additional In-depth Data Review”: State health departments may perform a review, or “audit”, of a hospital’s medical records to ensure the hospital defined and reported all appropriate HAIs to NHSN. The auditing process may identify more HAIs in a hospital than originally reported. As such, states that perform data audits may have a higher SIR when compared to states that do not perform data audits. In this report, credit is given to states that performed any type of audit of their hospitals’ medical or laboratory records prior to the start date of the report preparation for the report year data.