2016 National and State Healthcare-Associated Infections Progress Report

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

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

Each day, approximately one in 31 U.S. patients contracts 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 guideline work to push the country further toward the goal of eliminating HAIs.

2016 HAI Progress Report

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

Data Tables

• 2016 SIR Data
  • 2016 National and State HAI Progress Report SIR Data – Acute Care Hospitals excel icon[XLS – 816 KB]
  • 2016 National and State HAI Progress Report SIR Data – Critical Access Hospitals excel icon[XLS – 348 KB]
  • 2016 National and State HAI Progress Report SIR Data – Inpatient Rehabilitation Facilities excel icon[XLS – 121 KB]
  • 2016 National and State HAI Progress Report SIR Data – Long-Term Acute Care Hospital excel icon[XLS – 141 KB]
• 2016 SUR Data
  • 2016 National and State HAI Progress Report SUR Data – Acute Care Hospitals excel icon[XLS – 282 KB]
  • 2016 National and State HAI Progress Report SUR Data – Critical Access Hospital excel icon[XLS – 162 KB]
  • 2016 National and State HAI Progress Report SUR Data – Inpatient Rehabilitation Facilities excel icon[XLS – 92 KB]
  • 2016 National and State HAI Progress Report SUR Data – Long-Term Acute Care Hospitals excel icon[XLS – 100 KB]

Technical Appendix 

The 2016 National and State Healthcare-Associated Infections Data Report presents data reported to the National Healthcare Safety Network (NHSN) for the calendar year 2016. The healthcare-associated infection (HAI) data were reported in response to state or federal reporting requirements (via the Centers for Medicare and 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, 2016 data reported to NHSN through October 6, 2017 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 2016 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 pdf icon[PDF – 43 pages] 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.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 only calculated when at least five healthcare facilities reported 2016 data for the specific stratum, and/or 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 2016 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 are inclusive of data reported from all eligible locations within healthcare facilities, however the SIRs and SURs are also 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 a high volume of reported procedures. Due to insufficient pediatric SSI data at the state-level, the state SSI SIRs are calculated using data from adult patients only. 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 applicable specimens classified as hospital-onset (i.e., were collected on or after day 4 of admission) in which the specimen was collected 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 stratum that met the inclusion criteria 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 US 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 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 2016 SIR was compared against three benchmarks to assess progress in HAI prevention: the current 2016 national SIR, the state’s SIR from 2015, and the 2015 national baseline (i.e., compared to a value of 1). The 2016 national SIR was re-calculated for each state-to-national comparison with that state’s data removed from the 2016 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 2016 and 2015 SIRs provided information about HAIs in the state during 2016, and how this compared to the same state’s SIR from the prior year. The final comparison assess the state’s 2016 SIR against the national 2015 baseline of 1. 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 US were required to report select HAI data to NHSN in 2016 for participation in various CMS Quality Reporting Programs (QRPs).¹¹ The table below provides additional details on these requirements:

2016 Required Data Elements for Participation in CMS QRPs, by Facility Type

In addition to the NHSN data used to produce the SIRs in this report, the factsheets and the detailed technical tables, several external data sources were used to provide additional metrics. State health department HAI programs provided CDC with the status and specific requirements of state HAI reporting mandates to NHSN and efforts to validate 2016 HAI data. An indicator for a state mandate was provided for mandates enacted by either the state health department or the state’s hospital association. Validation efforts were classified into two categories for each HAI type – data checked for quality and additional in-depth data review. The following criteria were used to assign credit to states that performed data quality checks: state health department had access to 2016 NHSN data, performed regular data cleaning/quality checks on at least 6 months of 2016 data prior to October 1, 2017, 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 October 1, 2017, meaning the state health department reviewed hospital records to confirm proper case ascertainment and data entry into NHSN. Validation efforts should be taken into account 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 and may vary between states. 

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 May 8, 2018.
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 May 8, 2018.
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 May 8, 2018.
4. Centers for Disease Control and Prevention. Acute care hospital surveillance for central line-associated bloodstream infections. /nhsn/acute-care-hospital/clabsi/index.html. Accessed May 8, 2018.
5. Centers for Disease Control and Prevention. Acute care hospital surveillance for catheter-associated urinary tract infections. /nhsn/acute-care-hospital/cauti/index.html. Accessed May 8, 2018.
6. Centers for Disease Control and Prevention. Acute care hospital surveillance for surgical site infections. /nhsn/acute-care-hospital/ssi/index.html. Accessed May 8, 2018.
7. Centers for Disease Control and Prevention. Acute care hospital surveillance for C. difficile, MRSA, and other drug-resistant infections. Available at /nhsn/acute-care-hospital/cdiff-mrsa/index.html. Accessed May 8, 2018.
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 May 8, 2018.
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 May 8, 2018.
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 May 8, 2018.
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 May 8, 2018.

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

ORGANIZATIONS and HOSPITALS

Acute care hospital: 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 U.S.

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): 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): 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 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, with the exception of 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 HAI: For reporting to National Healthcare Safety Network, an infection 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 (antimicrobial resistance): Antibiotic resistance is the result of bacteria changing in ways that reduce or eliminate the effectiveness of antibiotics. Antimicrobial resistance is result of microorganisms changing in ways that reduce or eliminate the effectiveness of drugs, chemicals, or other agents used to cure or prevent infections. Antibiotic resistance is one type of antimicrobial resistance.

Carbapenem-resistant Enterobacteriaceae (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 a germ 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 hospitals within a state 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 method 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 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.

Statistical significance: Term used in the context of a statistical hypothesis test to determine if a finding is unlikely to have occurred by chance alone. A statistically significant test result means it is unlikely that the two groups sampled are different simply by chance alone (suggesting that the two populations sampled are, in fact, different). In this report, statistical hypothesis testing is used to compare a calculated Standardized Infection Ratio value (see SIR) to the value of 1.0. A statistical significant result from this test means there is statistical evidence that the calculated SIR is different than what would be predicted from the national data. In this report, statistical hypothesis testing is also used to compare two SIRs to each other.

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 2016 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 2016 SIR: A summary statistic calculated from all reported HAIs that occurred in the country in 2016. It was calculated as the total number of observed infections in the country, divided by the total number of predicted infections in the country in 2016. 

State 2016 SIR: A summary statistic calculated from all reported HAIs that occurred in an individual state in 2016. 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 in 2016.

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 2016 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 taken into account 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.

 Data Quality: State health departments may assess a hospital’s overall reported HAI data for data entry errors, outliers, or missing information. This does not involve reviewing medical records.

In this report, the following criteria were used to assign credit to states that performed data quality checks:

• State health department had access to 2016 data from NHSN.
• State health department performed quality checks on at least 6 months of 2016 NHSN data prior to October 1, 2017.
• State health department contacted hospitals when data errors, outliers, or missing information were found.

“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’ 2016 medical or laboratory records prior to October 1, 2017.