Applying the standardized infection ratio for reporting surgical site infections in Australian healthcare facilities.

Objective: We explored the utility of the standardized infection ratio (SIR) for surgical site infection (SSI) reporting in an Australian jurisdiction. Design: Retrospective chart review. Setting: Statewide SSI surveillance data from 2013 to 2019. Patients: Individuals who had cardiac bypass surgery (CABG), colorectal surgery (COLO), cesarean section (CSEC), hip prosthesis (HPRO), or knee prosthesis (KPRO) procedures. Methods: The SIR was calculated by dividing the number of observed infections by the number of predicted infections as determined using the National Healthcare Safety Network procedure-specific risk models. In line with a minimum precision criterion, an SIR was not calculated if the number of predicted infections was <1. Results: A SIR >0 (≥1 observed SSI, predicted number of SSI ≥1, no missing covariates) could be calculated for a median of 89.3% of reporting quarters for CABG, 75.0% for COLO, 69.0% for CSEC, 0% for HPRO, and 7.1% for KPRO. In total, 80.6% of the reporting quarters, when the SIR was not calculated, were due to no observed infections or predicted infections <1, and 19.4% were due to missing covariates alone. Within hospitals, the median percentage of quarters during which zero infections were observed was 8.9% for CABG, 20.0% for COLO, 25.4% for CSEC, 67.3% for HPRO, and 71.4% for KPRO. Conclusions: Calculating an SIR for SSIs is challenging for hospitals in our regional network, primarily because of low event numbers and many facilities with predicted infections <1. Our SSI reporting will continue to use risk-indexed rates, in tandem with SIR values when predicted number of SSI ≥1.

Measuring Healthcare-Associated Infection Outcomes: Enhanced Surveillance to Include Process Adherence for Quality Improvement.

To prevent healthcare-associated infections, there are a range of clinical practices that should be followed. For example, appropriate administration of prophylactic antibiotics [process] is essential to reduce risks of surgical site infections post-operatively [outcome]. Monitoring adherence to these processes provides insights into potential causes of infection. The Victorian Healthcare Associated Infection Surveillance System (VICNISS) captures process data in the same system as outcome data, thereby providing integrated data to support quality improvement within healthcare and reduce the burden of healthcare-associated infections.

Antibiotic Prescribing Practices for Prevention of Surgical Site Infections in Australia: Increased Uptake of National Guidelines after Surveillance and Reporting and Impact on Infection Rates.

BACKGROUND: Antimicrobial prophylaxis is the single most effective intervention to reduce risk of surgical site infections (SSIs); however, prescribing practices should be aligned with accepted and recommended surgical antibiotic prophylaxis (SAP) regimens to be effective. As part of a comprehensive surveillance network, SAP data are collated and analyzed for compliance with recommendations. Results are reported to hospitals for quality improvement purposes. In this study, statewide results were analyzed to ascertain changes over time and whether improved compliance was associated with a reduction in risk for SSI. METHODS: A standardized tool for monitoring SAP and SSIs was used in Victorian healthcare facilities. For the current study, data submitted for the period 2003-2015 were analyzed. Compliance with national recommendations (Australian Therapeutic Guidelines-Antibiotic) was used as the reference standard for antibiotic selection, timing, and duration Results: A total of 144,075 surgical procedures were surveyed during the study period. During this period, the proportion of patients receiving antibiotic agents according to national guidelines increased. Across all surgical groups, the odds ratio (OR) for appropriate SAP choice increased by 13%/year. Greatest improvement was seen for colorectal procedures (19%/year), with the smallest change observed for cholecystectomy and cardiac operations (9%/year). The OR for receiving an antibiotic agent at the recommended time increased by 12%/year and the odds of the antibiotic agent being discontinued within 24 hours by 27%/year. Non-compliance with a recommended SAP agent and timing was associated with an increased risk of SSI across all procedure groups (OR 1.33, 95% confidence interval 1.24-1.43). CONCLUSION: Sustained improvements in prescribing practices for SAP have been demonstrated through a comprehensive surveillance and reporting system. Non-compliance with SAP guidelines is associated with an increased risk for SSI. Quality improvement programs must focus on uptake and implementation of evidence-based guidelines.

Influenza vaccination uptake among Victorian healthcare workers: evaluating the success of a statewide program.

OBJECTIVE: Annual influenza vaccination is recommended for all Australian healthcare workers (HCWs). In 2014, a target vaccination uptake of 75% was set for Victorian healthcare facilities. This study aimed to determine the 2014 uptake, describe trends over time and propose an enhanced reporting framework. METHODS: Annual data submitted to the Victorian Healthcare Associated Infection Surveillance System (VICNISS) regarding HCW influenza were evaluated for 2005-2014. Faculty uptake - the number of vaccinations administered divided by total number of staff employed - was reported as a statewide aggregate and stratified by facility size (number of staff employed). RESULTS: In 2014, 78,885 HCWs were vaccinated across 93 healthcare facilities, corresponding to an overall uptake of 72.2%. During 2005-2014, small facilities (<100 HCWs) generally reported highest uptake while larger facilities (≥800 HCWs) recorded lowest uptake. Larger facilities recorded the greatest increase (+13.9%) when 2013 and 2014 seasons were compared. For all healthcare facility size categories, the highest uptake was observed in 2014. CONCLUSION: Influenza vaccination uptake in HCWs has successfully been introduced as a performance indicator in Victorian healthcare facilities and a peak uptake was reported in 2014. Varied trends are evident when uptake is stratified by number of employed HCWs, providing a feasible and meaningful method for benchmarking.

Central line-associated bloodstream infections in Australian intensive care units: Time-trends in infection rates, etiology, and antimicrobial resistance using a comprehensive Victorian surveillance program, 2009-2013.

BACKGROUND: The epidemiology of central line-associated bloodstream infections (CLABSI) in Australian intensive care units (ICUs) has not previously been reported. We sought to describe time-trends in CLABSI rates, infections by ICU peer-groups, etiology, and antimicrobial susceptibility of pathogens in a large cohort of Australian ICUs for the period January 1, 2009-December 31, 2013. METHODS: Using National Healthcare Safety Network methods, CLABSI surveillance in adult patients was performed by hospitals participating in the Victorian Healthcare Associated Infection Surveillance System (n = 29). Hospitals were grouped by location, sector, and teaching status. RESULTS: Overall, 384 CLABSI events were reported over 303,968 central venous catheter (CVC)-days, corresponding to a rate of 1.26/1,000 CVC-days (95% confidence interval, 1.14-1.40). Every 1-year increase was associated with a 26% reduction in CLABSI risk (risk ratio, 0.74, 95% confidence interval, 0.69-0.80; P < .001). The most frequently identified pathogens were Enterococcus spp (26.3%), followed by Candida spp (15.4%) and Staphylococcus aureus (13.3%). CLABSI due to Enterococcus spp, S aureus, and coagulase-negative Staphylococcus spp displayed significant reductions over time. CONCLUSIONS: Internationally accepted surveillance methods have been employed in Australia, demonstrating CLABSI rates comparable to medical/surgical ICUs in the United States and a reduction in pathogen-specific infections over a 5-year period.

Diminishing surgical site infections in Australia: time trends in infection rates, pathogens and antimicrobial resistance using a comprehensive Victorian surveillance program, 2002-2013.

OBJECTIVE: To evaluate time trends in surgical site infection (SSI) rates and SSI pathogens in Australia. DESIGN: Prospective multicenter observational cohort study. SETTING: A group of 81 Australian healthcare facilities participating in the Victorian Healthcare Associated Infection Surveillance System (VICNISS). PATIENTS: All patients underwent surgeries performed between October 1, 2002, and June 30, 2013. National Healthcare Safety Network SSI surveillance methods were employed by the infection prevention staff at the participating hospitals. INTERVENTION: Procedure-specific risk-adjusted SSI rates were calculated. Pathogen-specific and antimicrobial-resistant (AMR) infections were modeled using multilevel mixed-effects Poisson regression. RESULTS: A total of 183,625 procedures were monitored, and 5,123 SSIs were reported. Each year of observation was associated with 11% risk reduction for superficial SSI (risk ratio [RR], 0.89; 95% confidence interval [CI], 0.88-0.90), 9% risk reduction for deep SSI (RR, 0.91; 95% CI, 0.90-0.93), and 5% risk reduction for organ/space SSI (RR, 0.95; 95% CI, 0.93-0.97). Overall, 3,318 microbiologically confirmed SSIs were reported. Of these SSIs, 1,174 (35.4%) were associated with orthopedic surgery, 827 (24.9%) with coronary artery bypass surgery, 490 (14.8%) with Caesarean sections, and 414 (12.5%) with colorectal procedures. Staphylococcus aureus was the most frequently identified pathogen, and a statistically significant increase in infections due to ceftriaxone-resistant Escherichia coli was observed (RR, 1.37; 95% CI, 1.10-1.70). CONCLUSIONS: Standardized SSI surveillance methods have been implemented in Victoria, Australia. Over an 11-year period, diminishing rates of SSIs have been observed, although AMR infections increased significantly. Our findings facilitate the refinement of recommended surgical antibiotic prophylaxis regimens and highlight the need for a more expansive national surveillance strategy to identify changes in epidemiology.

Increasing incidence of Clostridium difficile infection, Australia, 2011-2012.

OBJECTIVES: To report the quarterly incidence of hospital-identified Clostridium difficile infection (HI-CDI) in Australia, and to estimate the burden ascribed to hospital-associated (HA) and community-associated (CA) infections. DESIGN, SETTING AND PATIENTS: Prospective surveillance of all cases of CDI diagnosed in hospital patients from 1 January 2011 to 31 December 2012 in 450 public hospitals in all Australian states and the Australian Capital Territory. All patients admitted to inpatient wards or units in acute public hospitals, including psychiatry, rehabilitation and aged care, were included, as well as those attending emergency departments and outpatient clinics. MAIN OUTCOME MEASURES: Incidence of HI-CDI (primary outcome); proportion and incidence of HA-CDI and CA-CDI (secondary outcomes). RESULTS: The annual incidence of HI-CDI increased from 3.25/10 000 patient-days (PD) in 2011 to 4.03/10 000 PD in 2012. Poisson regression modelling demonstrated a 29% increase (95% CI, 25% to 34%) per quarter between April and December 2011, with a peak of 4.49/10 000 PD in the October-December quarter. The incidence plateaued in January-March 2012 and then declined by 8% (95% CI, - 11% to - 5%) per quarter to 3.76/10 000 PD in July-September 2012, after which the rate rose again by 11% (95% CI, 4% to 19%) per quarter to 4.09/10 000 PD in October-December 2012. Trends were similar for HA-CDI and CA-CDI. A subgroup analysis determined that 26% of cases were CA-CDI. CONCLUSIONS: A significant increase in both HA-CDI and CA-CDI identified through hospital surveillance occurred in Australia during 2011-2012. Studies are required to further characterise the epidemiology of CDI in Australia.

Staphylococcus aureus bloodstream infection in Australian hospitals: findings from a Victorian surveillance system.

OBJECTIVES: To determine the burden of disease and trend over time for rates of Staphylococcus aureus bloodstream (SAB) infections in Victorian health care services. DESIGN AND SETTING: Uniform data on all SAB infection events (methicillin-sensitive and methicillin-resistant isolates) were collected from all public and some private hospitals in Victoria using a standardised electronic data collection tool. Data were analysed for the period 1 January 2010 to 31 December 2012. MAIN OUTCOME MEASURES: Overall and quarterly aggregate SAB and methicillin-resistant S. aureus (MRSA) bloodstream infection rates per 10,000 occupied bed-days (OBDs); rates of health care-associated (HA) infections compared with a benchmark of no more than 2/10,000 OBDs. RESULTS: Data from 119 public and four private hospitals were analysed. The cumulative aggregate SAB infection rate was 1.0/10,000 OBDs (95% CI, 0.9-1.0/10,000 OBDs). Overall, 1335/3205 SAB infection events (41.7%) were health care-associated. Of these, 26.2% occurred within 48 hours of hospitalisation and were most frequently associated with an indwelling medical device. Quarterly HA-SAB infection rates diminished from 1.4 to 0.7/10,000 OBDs (P < 0.001). A median of four health care services each quarter exceeded the benchmark of 2.0/10,000 OBDs. HA-MRSA bloodstream infection rates diminished from 0.4 to 0.1/10,000 OBDs (P < 0.001), with a cumulative aggregate rate of 0.2/10,000 OBDs. CONCLUSIONS: Continuous surveillance for SAB infection showed a significant reduction in rates across Victoria during the first 3 years of a coordinated program. Early onset, device-related SAB infections are an important target for prevention strategies.

Impact of vancomycin surgical antibiotic prophylaxis on the development of methicillin-sensitive staphylococcus aureus surgical site infections: report from Australian Surveillance Data (VICNISS).

OBJECTIVE: To compare risks for developing surgical site infection (SSI) due to Staphylococcus aureus when vancomycin is used for antibiotic prophylaxis with risks when a ß-lactam antibiotic is administered for prophylaxis. BACKGROUND: Vancomycin is often used as surgical antibiotic prophylaxis for major surgery. In nonsurgical populations, there is evidence that vancomycin is less effective for prevention and treatment of methicillin-sensitive Staphylococcus aureus (MSSA) infections. Since 2002, the Victorian Healthcare Associated Surveillance System (VICNISS) has used standardized methods for infection surveillance in Australia, including any prophylactic antibiotic agent administered before surgical procedures. METHODS: Surveillance records were obtained for patients undergoing 4 clean surgical procedures during the period of November 2002 to June 2009. Logistic regression analysis was used to examine risk factors for infection, including age, procedure duration, American Society of Anesthesiologists score, and choice and timing of antibiotic prophylaxis. RESULTS: The data set consisted of 22,549 procedures, including cardiac bypass and hip and knee arthroplasty procedures. Vancomycin prophylaxis was administered in 1610 cases and a ß-lactam antibiotic for 20,939 cases. A total of 754 SSIs were recorded. The most frequent pathogens were MSSA, methicillin-resistant Staphylococcus aureus, and Pseudomonas species. The adjusted odds ratio (OR) for an SSI with MSSA was 2.79, where vancomycin prophylaxis was administered (P < 0.001). For methicillin-resistant Staphylococcus aureus infection, the adjusted OR for vancomycin was 0.44 (P = 0.05), whereas for Pseudomonas infection, it was 0.96 (P = 0.95). CONCLUSIONS: In a large Australian study population, prophylaxis with vancomycin was found to be associated with an increased risk of SSI due to MSSA when compared with prophylaxis with a ß-lactam antibiotic. Given the potential for poorer surgical outcomes in the setting of indiscriminate prophylactic vancomycin use, measures to improve adherence to guidelines for restricted administration of prophylactic vancomycin are supported.

Validation of statewide surveillance system data on central line-associated bloodstream infection in intensive care units in Australia.

OBJECTIVE: To measure the interobserver agreement, sensitivity, specificity, positive predictive value, and negative predictive value of data submitted to a statewide surveillance system for identifying central line-associated bloodstream infection (BSI). DESIGN: Retrospective review of hospital medical records comparing reported data with gold standard according to definitions of central line-associated BSI. SETTING: Six Victorian public hospitals with more than 100 beds. METHODS: Reporting of surveillance outcomes was undertaken by infection control practitioners at the hospital sites. Retrospective evaluation of the surveillance process was carried out by independent infection control practitioners from the Victorian Hospital Acquired Infection Surveillance System (VICNISS). A sample of records of patients reported to have a central line-associated BSI were assessed to determine whether they met the definition of central line-associated BSI. A sample of records of patients with bacteremia in the intensive care unit during the assessment period who were not reported as having central line-associated BSI were also assessed to see whether they met the definition of central line-associated BSI. RESULTS: Records of 108 patients were reviewed; the agreement between surveillance reports and the VICNISS assessment was 67.6% (k = 0.31). Of the 46 reported central line-associated BSIs, 27 were confirmed to be central line-associated BSIs, for a positive predictive value of 59% (95% confidence interval [CI], 43%-73%). Of the 62 cases of bacteremia reviewed that were not reported as central line-associated BSIs, 45 were not associated with a central line, for a negative predictive value of 73% (95% CI, 60%-83%). Estimated sensitivity was 35%, and specificity was 87%. The positive likelihood ratio was 3.0, and the negative likelihood ratio was 0.72. DISCUSSION: The agreement between the reporting of central line-associated BSI and the gold standard application of definitions was unacceptably low. False-negative results were problematic; more than half of central line-associated BSIs may be missed in Victorian public hospitals.

Impact of revising the National Nosocomial Infection Surveillance System definition for catheter-related bloodstream infection in ICU: reproducibility of the National Healthcare Safety Network case definition in an Australian cohort of infection control professionals.

BACKGROUND: Effective and comparable surveillance for central venous catheter-related bloodstream infections (CLABSIs) in the intensive care unit requires a reproducible case definition that can be readily applied by infection control professionals. METHODS: Using a questionnaire containing clinical cases, reproducibility of the National Nosocomial Infection Surveillance System (NNIS) surveillance definition for CLABSI was assessed in an Australian cohort of infection control professionals participating in the Victorian Hospital Acquired Infection Surveillance System (VICNISS). The same questionnaire was then used to evaluate the reproducibility of the National Healthcare Safety Network (NHSN) surveillance definition for CLABSI. Target hospitals were defined as large metropolitan (1A) or other large hospitals (non-1A), according to the Victorian Department of Human Services. Questionnaire responses of Centers for Disease Control and Prevention NHSN surveillance experts were used as gold standard comparator. RESULTS: Eighteen of 21 eligible VICNISS centers participated in the survey. Overall concordance with the gold standard was 57.1%, and agreement was highest for 1A hospitals (60.6%). The proportion of congruently classified cases varied according to NNIS criteria: criterion 1 (recognized pathogen), 52.8%; criterion 2a (skin contaminant in 2 or more blood cultures), 83.3%; criterion 2b (skin contaminant in 1 blood culture and appropriate antimicrobial therapy instituted), 58.3%; non-CLABSI cases, 51.4%. When survey questions regarding identification of cases of CLABSI criterion 2b were removed (consistent with the current NHSN definition), overall percentage concordance increased to 62.5% (72.2% for 1A centers). CONCLUSION: Further educational interventions are required to improve the discrimination of primary and secondary causes of bloodstream infection in Victorian intensive care units. Although reproducibility of the CLABSI case definition is relatively poor, adoption of the revised NHSN definition for CLABSI is likely to improve the concordance of Victorian data with international centers.

A user assessment of a smaller hospital surveillance program.

Forty-five infection control nurses responded to a survey that assessed a smaller hospital (<100 acute care beds) surveillance program. Most respondents (96.6%) agreed that participation in the program was useful. Only a few program elements that need further development were identified. Approximately half (52.3%) of the respondents agreed that the surveillance reports were easy to understand. The most frequent (72.9%) use of these reports was to present information to accreditation organizations. Approximately half (46.2% and 50%, respectively) of the respondents disagreed that the Web-based education package or the workplace visits by "educators" were useful.

MRSA infections in smaller hospitals, Victoria, Australia.

BACKGROUND: Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) cause significant morbidity, mortality, and associated costs. METHODS: Trained infection control (IC) nurses in 84 smaller (<100 acute beds) hospitals during a 20-month period collected data on MRSA infections. RESULTS: The aggregate rate for all MRSA infections confirmed by the Victorian Hospital Acquired Infection Surveillance System Coordinating Centre IC nurse was 1.5 per 10,000 acute care occupied bed days (OBDs) (95% CI: 1.2-1.8). MRSA infections of 0.5 per 10,000 OBDs were detected >48 hours after admission (95% CI: 0.3-0.7). The aggregate rate for MRSA infections in sterile sites was 0.2 per 10,000 OBDs (95% CI: 0.0-0.4) and in nonsterile sites was 1.3 per 10,000 OBDs (95% CI: 1.0-1.6). CONCLUSION: The results suggested that serious MRSA infections in Victoria's smaller hospitals are an infrequent event. Most are "inherited" either from the community or other health care facilities.

An alternative scoring system to predict risk for surgical site infection complicating coronary artery bypass graft surgery.

OBJECTIVE: To analyze the risk factors for surgical site infection (SSI) complicating coronary artery bypass graft (CABG) surgery and to create an alternative SSI risk score based on the results of multivariate analysis. METHODS: A prospective cohort study involving inpatient and laboratory-based surveillance of patients who underwent CABG surgery over a 27-month period from January 1, 2003 through March 31, 2005. Data were obtained from 6 acute care hospitals in Victoria, Australia, that contributed surveillance data for SSI complicating CABG surgery to the Victorian Hospital Acquired Infection Surveillance System Coordinating Centre and the Australasian Society of Cardiac and Thoracic Surgeons, also in Victoria. RESULTS: A total of 4,633 (93%) of the 4,987 patients who underwent CABG surgery during this period were matched in the 2 systems databases. There were 286 SSIs and 62 deep or organ space sternal SSIs (deep or organ space sternal SSI rate, 1.33%). Univariate analysis revealed that diabetes mellitus, body mass index (BMI) greater than 35, and receipt of blood transfusion were risk factors for all types of SSI complicating CABG surgery. Six multivariate analysis models were created to examine either preoperative factors alone or preoperative factors combined with operative factors. All models revealed diabetes and BMI of 30 or greater as risk factors for SSI complicating CABG surgery. A new preoperative scoring system was devised to predict sternal SSI, which assigned 1 point for diabetes, 1 point for BMI of 30 or greater but less than 35, and 2 points for BMI of 35 or greater. Each point in the scoring system represented approximately a doubling of risk of SSI. The new scoring system performed better than the National Nosocomial Infections Surveillance System (NNIS) risk index at predicting SSI. CONCLUSION: A new weighted scoring system based on preoperative risk factors was created to predict sternal SSI risk following CABG surgery. The new scoring system outperformed the NNIS risk index. Future studies are needed to validate this scoring system.

Validation of coronary artery bypass graft surgical site infection surveillance data from a statewide surveillance system in Australia.

OBJECTIVE: To measure the accuracy and determine the positive predictive value (PPV) and negative predictive value (NPV) of data submitted to a statewide surveillance system for identifying surgical site infection (SSI) complicating coronary artery bypass graft (CABG) surgery. DESIGN: Retrospective review of hospital medical records comparing SSI data with surveillance data submitted by infection control consultants (ICCs). SETTING: Victorian Hospital Acquired Infection Surveillance System (VICNISS) Coordinating Centre in Victoria, Australia. PATIENTS: All patients reported to have an SSI following CABG surgery and a random sample of approximately 10% of patients reported not to have an SSI following CABG surgery. RESULTS: The VICNISS ascertainment rate for CABG procedures in Victoria was 95%. One hundred sixty-nine medical records were reviewed, and reviewers agreed with ICCs about 46 (96%) of the patients reported as infected by the ICCs and 31 (91%) of the patients identified with a sternal SSI by the ICCs. In one-third of SSIs, the depth of SSI documented by ICCs was discordant with that documented by the reviewers. Disagreement about patients with donor site SSI was frequent. When the review findings were used as the reference standard, the PPV for ICC-reported SSI was 96% (95% confidence interval [CI], 86%-99%), and the NPV was 97% (95% CI, 92%-99%). For ICC-reported sternal SSI, the PPV was 91% (95% CI, 76%-98%) and the NPV was 98% (95% CI, 94%-100%). CONCLUSIONS: There was broad agreement on the number of infected patients and the number of patients with sternal SSI. However, discordance was frequent with respect to the depth of sternal SSI and the identification of donor site SSI. We recommend modifications to the methodology for National Nosocomial Infection Surveillance System-based surveillance for SSI following CABG surgery.