1 Executive Summary

Pennsylvania was one of the first states to recognize the harmful impact that healthcare-associated infections (HAIs) had on patient outcomes and quality of life related to additional medical treatment, loss of time, and financial burden. As a result, in 2007, the Pennsylvania General Assembly amended the Medical Care Availability and Reduction of Error (MCARE) Act by adding a new chapter (Pennsylvania Act 52) to address the reduction and prevention of HAIs in Pennsylvania. This law includes requirements for hospitals to report all HAI events into the National Healthcare Safety Network (NHSN), a secure internet-based data collection/reporting system managed by the Division of Healthcare Quality Promotion at the Centers for Disease Control and Prevention (CDC). The use of NHSN provides standardized HAI case definitions and allows for analysis and comparison to hospitals located throughout the nation. As required by Act 52, the Department analyzes HAI data reported to NHSN, summarizes the findings and releases an annual report that documents progress that Pennsylvania hospitals have made in implementing HAI prevention strategies to encourage statewide reduction of HAIs.

This 2019 report is the 12th report to be released by the Department and the fourth to use an interactive online format. These data demonstrate an overall continued decline in HAIs. However, the reader must be aware that this report does not include data from nursing homes, long-term care facilities, ambulatory surgical centers, or other outpatient care centers and only includes information from Pennsylvania acute care, critical access, inpatient rehabilitation, long-term acute care, psychiatric, and children’s hospitals for the calendar year 2019. Results are presented for a subset of NHSN HAI types, two device utilization rates, surgical site infections (SSI) following seven types of surgical procedures, and two proxy infection events [Laboratory-Identified Events (LabID)]. Included are:

  1. Central line-associated bloodstream infections (CLABSI)
  2. Catheter-associated urinary tract infections (CAUTI)
  3. Surgical site infections (SSI) for seven procedure types
    • Abdominal hysterectomies (HYST)
    • Colon surgeries (COLO)
    • Cardiac surgeries (CARD)
    • Coronary bypass with chest incision and donor incisions (CBG with two incisions)
    • Coronary bypass with chest incision only (CBG with one incision)
    • Hip prosthesis (HPRO)
    • Knee prosthesis (KPRO)
  4. Urinary catheter utilization
  5. Central line utilization
  6. Clostridioides difficile lab events (CDI LabID)
  7. Methicillin-resistant Staphylococcus aureus blood specimen events (MRSA LabID)

Other HAIs occur but are not included in this report. These may include respiratory illnesses and surgical site infections that follow other types of surgeries. This report presents HAI results using two NHSN metrics to gauge the progress in reducing HAIs.

  1. The standardized infection ratio (SIR) compares the number of reported infections with the number of predicted infections based on 2015 baseline data. It adjusts for several risk factors that have been found to be significantly associated with differences in infection incidence. Factors may be either facility-related or, for surgical site infections, patient characteristics.
  2. The standardized utilization ratio (SUR) compares the actual number of device days reported with the number of predicted device days based on 2015 national baseline data. It is adjusted for facility characteristics.

In both metrics, the predicted number is calculated from the 2015 NHSN national baseline data, which uses 2015 reported HAI data.

The SIR and SUR are useful metrics to compare one facility to similar facilities in the rest of the country. Below are rules to interpret the value of a SIR:

  • If the SIR is greater than 1.0, then more HAIs were observed than predicted, based on the 2015 national aggregate data.
  • If the SIR equals 1.0, then the same number of HAIs were observed as predicted, based on the 2015 national aggregate data.
  • If the SIR is less than 1.0, then fewer HAIs were observed than predicted, based on the 2015 national aggregate data.

Comparisons of SIR and SUR values can only be made when the baseline data are from the same timeframe. Readers are cautioned not to compare SIR values in this report to Pennsylvanian HAI reports prior to 2016. SIR values in this report can be compared to data from the 2016, 2017 and 2018 annual reports and CDC HAI progress reports that use the 2015 national baseline.

To fully interpret SIR and SUR values, it’s best to examine not only how large or small the SIR or SUR value is when compared to 1.0, but also examine the 95% confidence interval. The 95% confidence interval is a range of values in which a high degree of confidence exists that the true SIR (or SUR) lies within that range. If the 95% confidence interval does not include 1.0, it is considered “statistically significant.” The combination of both approaches is considered the best way to evaluate a SIR or SUR value. Below are rules for interpreting the 95% confidence interval.

95% Confidence Interval:

  • The 95% confidence interval is a range of values in which a high degree of confidence exists that the true SIR (or SUR) lies within that range.
  • If the confidence interval does not include 1.0, then the SIR is significantly different than 1.0 (i.e., the number of observed infections is significantly different than the number predicted).
    • Example: Example: 95% confidence interval = (0.85, 0.92) One can be 95% certain that the true value is between 0.85 and 0.92 and not different than 1.
  • If the confidence interval includes the value of 1.0, then the SIR is not significantly different than 1.0 (i.e., the number of observed infections is not significantly different than the number predicted).
    • Example: 95% confidence interval = (0.85, 1.24) One can be 95% certain that the true value is not different than 1.0.
  • If the SIR is 0.000 (i.e., the infection count is 0 and the number of predicted infections is >= 1.0), the lower bound of the 95% confidence interval will not be calculated.
    • Example: 95% confidence interval = (0, 1.49) One can be 95% certain that the true value is between 0 and 1.49 and is not different than 1.0.
    • Example: 95% confidence interval = (0, 0.85) One can be 95% certain that the true value is between 0 and 0.85 and is less than 1.0.

The metrics are calculated using aggregate data reported by included Pennsylvania hospitals and are presented for the entire commonwealth, by hospital type and by individual hospitals.

Healthcare-Associated Infections in Hospital Settings by Type: Number of Infections (Cases), Standardized Infection Ratio (SIR), and Number of Infections Needed to Prevent to Reach National SIR Goal (Goal) | Pennsylvania 2019

Metric Acute Critical Access Children’s Long-Term Acute Psychiatric Inpatient Rehabilitation
CAUTI
Cases 1,017 3 16 60 3 74
SIR 0.76 (0.71, 0.81) 0.42 (0.11, 1.14) 1.24 (0.73, 1.97) 1.04 (0.80, 1.33) 1.05 (0.27, 2.86) 1.05 (0.83, 1.32)
Goal* (SIR=0.75) 14 Goal met 6 17 1 21
CLABSI
Cases 785 2 117 76 0 16
SIR 0.68 (0.63, 0.73) 1.49 (0.25, 4.92) 0.88 (0.73, 1.05) 0.67 (0.53, 0.84) 0 (0.00, 2.87) 0.69 (0.41, 1.10)
Goal* (SIR=0.5) 207 1 50 20 Goal met 4
COLO SSI
Cases 332 1 2 Not measured Not measured Not measured
SIR 0.79 (0.71, 0.88) 0.52 (0.09, 1.72)
Goal* (SIR=0.7) 39 Goal met Goal met
HYST SSI
Cases 80 0 0 Not measured Not measured Not measured
SIR 0.86 (0.69, 1.07)
Goal* (SIR=0.7) 15 Goal met Goal met
CDI LabID
Cases 2,598 Not measured Not measured 77 Not measured 178
SIR 0.65 (0.62, 0.67) 0.54 (0.43, 0.68) 0.64 (0.55, 0.74)
Goal* (SIR=0.7) Goal met Goal met Goal met
MRSA LabID
Cases 328 Not measured Not measured 7 Not measured 8
SIR 0.72 (0.64, 0.80) 0.3 (0.13, 0.59) 0.66 (0.31, 1.26)
Goal* (SIR=0.5) 99 Goal met 2
* Goal: The number of cases that needed to be prevented in order to meet the 2020 national reduction SIR goal set by United States Department of Health and Human Services (HHS)

2019 Catheter-associated urinary tract infections (CAUTIs) Among the 1,201,008 patient urinary catheter days, 1,173 CAUTIs were reported to NHSN from 286 Pennsylvania hospitals. The state SIR was 0.79, which was statistically significantly lower than the 2015 NHSN national baseline (95% CI:(0.74, 0.83)). The SIR in children’s hospitals was highest (SIR: 1.24, 95% CI: (0.73, 1.97)), and it was lowest in critical access hospitals (SIR: 0.42, 95% CI: (0.11, 1.14)). Sixteen hospitals had a SIR that was statistically significantly greater than 1.0. To meet the 2020 United States Department of Health and Human Services (HHS) HAI CAUTI goal of a 25% reduction in CAUTIs compared to those predicted in 2015 in the commonwealth, 57 additional infections needed to be prevented . The urinary catheter SUR was 0.77 (95% CI: (0.77, 0.77)) among 161 acute care hospitals. The SUR was highest among psychiatric hospitals (SUR: 1.1, 95% CI: (1.05, 1.15)).

2019 Central line-associated blood stream infections (CLABSIs) Among 1,389,426 patient central line days, 996 CLABSIs were reported to NHSN from 280 hospitals.The state SIR was 0.7, statistically significantly less than the 2015 national baseline (95% CI: (0.66, 0.74)). The number of total CLABSIs from all hospitals, except critical access hospitals, was below the number predicted in 2015. The SIR from acute care and long-term acute care hospitals reached statistical significance (SIR Acute : 0.68, 95% CI: (0.63, 0.73), SIR LT Acute: 0.67, 95% CI: (0.53, 0.84)). Nine hospitals had a statistically significant SIR that was greater than 1.0. To meet the 2020 HHS HAI CLABSI goal of a 50% reduction in cases compared with the number predicted in 2015in the commonwealth, 282 reported additional infections needed to be prevented. Pennsylvania acute care hospitals reported using fewer central lines than predicted (SUR: 0.8, 95% CI: (0.80, 0.81)).

2019 Surgical site infections (SSI) In 2019, 165 Pennsylvania hospitals performed at least one of the seven surgical procedures tracked for surgical site infection surveillance. Hospitals reported 118,368 of these surgical procedures and 825 (deep tissue or organ space) SSIs were later identified. Knee replacement surgery was the most common (N= 42,316) and represented 35.7% of all the surgical procedures. The SIR values for each surgery type were 0.84 (95% CI:(0.57, 1.20)) for cardiac surgeries, 0.73 (95% CI:(0.54, 0.97)) for cardiac bypass surgeries (CBG) with two incisions, 0.23 (95% CI:(0.04, 0.75)) for CBG with one incision, 0.79 (95% CI:(0.71, 0.88)) for colon surgeries (COLO), 1.03 (95% CI:(0.90, 1.18)) for hip replacement surgeries (HPRO), 0.86 (95% CI:(0.68, 1.06)) for abdominal hysterectomy surgeries (HYST), and 0.95 (95% CI:(0.80, 1.12)) for knee replacement surgeries (KPRO). Seven hospitals had a statistically significant KPRO SIR value greater than 1.0. Four hospitals had a statistically significant SIR value greater than 1.0 for HPRO . Three hospitals a had statistically significant COLO SIR value greater than 1.0. One hospital had a statistically significant CARD SIR value greater than 1.0. Three hospitals had a statistically significant COLO SIR value less than 1.0. One hospital had a statistically significant HPRO SIR value that was less than 1.0. To meet the 2020 HHS COLO SSI goal of a 30% reduction in cases compared with the number predicted in 2015 in the commonwealth, 38 additional infections needed to be prevented. To meet the same 2020 HHS HYST goalin the commonwealth, 15 additional infections needed to be prevented.

2019 Clostridioides difficile infections (CDI LabID) Among the 7,235,826 patient days, 2,853 CDI LabID events were reported from 248 hospitals. CDI LabID events from children’s, critical access, and psychiatric hospitals were not required to be reported into NHSN. The SIR values from all three facility types were statistically significantly lower than predicted from the 2015 national baseline. The SIR from acute care hospitals was 0.65 (95%CI: (0.62, 0.67)). The SIR value from long-term acute care hospitals was 0.54 (95%CI: (0.43, 0.68)). The SIR value from inpatient rehabilitation facilities was 0.64 (95%CI: (0.55, 0.74)). Three facilities had statistically significant SIR values greater than 1.0. The state met the 2020 HHS HAI CDI goal of a 30% reduction in cases compared with the number predicted in 2015.

2019 Methicillin-resistant Staphylococcus aureus Blood Infections (MRSA LabID) Among the 7,659,636 patient days, 343 MRSA LabID events were reported from 248 hospitals. MRSA LabID events from children’s, critical access, and psychiatric hospitals are not required to be reported to NHSN. The state SIR was 0.7, statistically lower than predicted from the 2015 national baseline (95% CI: (0.62, 0.77)). The highest SIR was among acute care hospitals (SIR 0.72, 95% CI: (0.64, 0.80)). No hospitals had a statistically significant SIR value greater than 1.0. To meet the 2020 HHS MRSA LabID goal of a 50% reduction in cases in the commonwealth compared with the number predicted in 2015, 97 MRSA LabID events needed to be prevented.

According to CDC, 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 US health care facilities1. While much progress has been made, opportunities still exist to prevent HAIs in a variety of settings. A review article that evaluated the effectiveness of multifaceted interventions across different HAI from 2005 - 2016 found that 54.3% of CAUTIs, 45.9% of CLABSIs and 46.1% of SSIs can be prevented2.The Department recommends that hospitals train and audit staff and processes to ensure adherence to national guidelines, implement multifaceted interventions to prevent HAIs and perform surveillance to identify HAI clusters and outbreaks.