To define the relationships between age, sex and hospital-acquired infection (HAI) rates in a national cohort of hospitalized patients.

Analysis of chart-abstracted Medicare Patient Safety Monitoring System data from randomly selected medical records of patients hospitalized between January 1, 2009, and December 31, 2011, for acute cardiovascular disease, pneumonia, or major surgery associated with 1 of 6 HAIs. Patients were stratified into 6 groups. We then analyzed the association of age, sex, and 2 outcomes; the rate of occurrence of HAI for patients who were at risk and the rate of patients having at least 1 HAI.

Among 85,461 patients, all groups except younger female surgical patients had higher catheter-associated urinary tract infection (CAUTI) rates than male patients. After adjustment for comorbidities, there was no overall evidence of higher HAI rates among elderly patients. In patients with acute cardiovascular disease, women had higher rates of HAIs. Among patients with pneumonia, there was no significant difference in the rate of HAIs among most age and sex groups. Among surgical patients, all age and sex groups had a significantly higher adjusted rate of developing at least 1 HAI except females 65 years of age or older. Similar results were seen for the outcome of the occurrence rate of HAIs.

There was not an overall increased risk of HAIs among older patients hospitalized for acute cardiovascular disease, pneumonia, and major surgery after adjustment for comorbidities. The relationship between sex and the rate of HAIs varied depending upon the underlying acute reason for hospitalization.

Little is known about racial and ethnic disparities in the occurrence of healthcare-associated infections (HAIs) in hospitalized patients.

To determine whether racial/ethnic disparities exist in the rate of occurrence of HAIs captured in the Medicare Patient Safety Monitoring System (MPSMS).

Chart-abstracted MPSMS data from randomly selected all-payer hospital discharges of adult patients (18 years old or above) between January 1, 2009, and December 31, 2011, for 3 common medical conditions: acute cardiovascular disease (composed of acute myocardial infarction and heart failure), pneumonia, and major surgery for 6 HAI measures (hospital-acquired antibiotic-associated Clostridium difficile, central line-associated bloodstream infections, postoperative pneumonia, catheter-associated urinary tract infections, hospital-acquired methicillin-resistant Staphylococcus aureus, and ventilator-associated pneumonia).

The study sample included 79,019 patients who had valid racial/ethnic information divided into 6 racial/ethnic groups—white non-Hispanic (n = 62,533), black non-Hispanic (n = 9,693), Hispanic (n = 4,681), Asian (n = 1,225), Native Hawaiian/Pacific Islander (n = 94), and other (n = 793)—who were at risk for at least 1 HAI. The occurrence rate for HAIs was 1.1% for non-Hispanic white patients, 1.3% for non-Hispanic black patients, 1.5% for Hispanic patients, 1.8% for Asian patients, 1.7% for Native Hawaiian/Pacific Islander patients, and 0.70% for other patients. Compared with white patients, the age/gender/comorbidity-adjusted odds ratios of occurrence of HAIs were 1.1 (95% confidence interval [CI], 0.99-1.23), 1.3 (95% CI, 1.15-1.53), 1.4 (95% CI, 1.07-1.75), and 0.7 (95% CI, 0.40-1.12) for black, Hispanic, Asian, and a combined group of Native Hawaiian/Pacific Islander and other patients, respectively.

Among patients hospitalized with acute cardiovascular disease, pneumonia, and major surgery, Asian and Hispanic patients had significantly higher rates of HAIs than white non-Hispanic patients.

To determine rates of blood culture contamination comparing 3 strategies to prevent intensive care unit (ICU) infections: screening and isolation, targeted decolonization, and universal decolonization.

Pragmatic cluster-randomized trial.

Forty-three hospitals with 74 ICUs; 42 of 43 were community hospitals.

Patients admitted to adult ICUs from July 1, 2009, to September 30, 2011.

After a 6-month baseline period, hospitals were randomly assigned to 1 of 3 strategies, with all participating adult ICUs in a given hospital assigned to the same strategy. Arm 1 implemented methicillin-resistant Staphylococcus aureus (MRSA) nares screening and isolation, arm 2 targeted decolonization (screening, isolation, and decolonization of MRSA carriers), and arm 3 conducted no screening but universal decolonization of all patients with mupirocin and chlorhexidine (CHG) bathing. Blood culture contamination rates in the intervention period were compared to the baseline period across all 3 arms.

During the 6-month baseline period, 7,926 blood cultures were collected from 3,399 unique patients: 1,099 sets in arm 1, 928 in arm 2, and 1,372 in arm 3. During the 18-month intervention period, 22,761 blood cultures were collected from 9,878 unique patients: 3,055 sets in arm 1, 3,213 in arm 2, and 3,610 in arm 3. Among all individual draws, for arms 1,2, and 3, the contamination rates were 4.1%, 3.9%, and 3.8% for the baseline period and 3.3%, 3.2%, and 2.4% for the intervention period, respectively. When we evaluated sets of blood cultures rather than individual draws, the contamination rate in arm 1 (screening and isolation) was 9.8% (N = 108 sets) in the baseline period and 7.5% (N = 228) in the intervention period. For arm 2 (targeted decolonization), the baseline rate was 8.4% (N = 78) compared to 7.5% (N = 241) in the intervention period. Arm 3 (universal decolonization) had the greatest decrease in contamination rate, with a decrease from 8.7% (N = 119) contaminated blood cultures during the baseline period to 5.1% (N = 184) during the intervention period. Logistic regression models demonstrated a significant difference across the arms when comparing the reduction in contamination between baseline and intervention periods in both unadjusted (P = .02) and adjusted (P = .02) analyses. Arm 3 resulted in the greatest reduction in blood culture contamination rates, with an unadjusted odds ratio (OR) of 0.56 (95% confidence interval [CI], 0.044-0.71) and an adjusted OR of 0.55 (95% CI, 0.43-0.71).

In this large cluster-randomized trial, we demonstrated that universal decolonization with CHG bathing resulted in a significant reduction in blood culture contamination.

To estimate and compare the impact on healthcare costs of 3 alternative strategies for reducing bloodstream infections in the intensive care unit (ICU): methicillin-resistant Staphylococcus aureus (MRSA) nares screening and isolation, targeted decolonization (ie, screening, isolation, and decolonization of MRSA carriers or infections), and universal decolonization (ie, no screening and decolonization of all ICU patients).

Cost analysis using decision modeling.

We developed a decision-analysis model to estimate the health care costs of targeted decolonization and universal decolonization strategies compared with a strategy of MRSA nares screening and isolation. Effectiveness estimates were derived from a recent randomized trial of the 3 strategies, and cost estimates were derived from the literature.

In the base case, universal decolonization was the dominant strategy and was estimated to have both lower intervention costs and lower total ICU costs than either screening and isolation or targeted decolonization. Compared with screening and isolation, universal decolonization was estimated to save $171,000 and prevent 9 additional bloodstream infections for every 1,000 ICU admissions. The dominance of universal decolonization persisted under a wide range of cost and effectiveness assumptions.

A strategy of universal decolonization for patients admitted to the ICU would both reduce bloodstream infections and likely reduce healthcare costs compared with strategies of MRSA nares screening and isolation or screening and isolation coupled with targeted decolonization.

Studies conducted in Europe have observed resistance to trace metals such as zinc chloride and copper sulfate in livestock-associated Staphylococcus aureus. This study was conducted to determine the prevalence of zinc and cadmium resistance in S. aureus isolated in the United States.

Cross-sectional study of convenience sample of S. aureus isolates.

Three hundred forty-nine S. aureus isolates, including methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) obtained from human, swine, and retail meat were included in the sample set.

Polymerase chain reaction was used to test for the presence of genes for zinc and cadmium resistance (czrC), methicillin resistance (mecA), and staphylococcal complement inhibitor (scn). Antibiotic susceptibility of isolates was tested using the broth microdilution method. Data were analyzed using the multivariable logistic regression method.

Twenty-nine percent (102/349) of S. aureus isolates were czrC positive. MRSA isolates were more likely to be czrC positive compared to MSSA (MRSA czrC positive: 12/61, 19.6%; MSSA czrC positive: 12/183, 6.6%). After adjustment for oxacillin and clindamycin susceptibility in analysis, multidrug-resistant S. aureus was observed to have low odds of being czrC positive (P = .03). The odds of being czrC positive were observed to be significantly high in tetracycline-resistant S. aureus isolated from noninfection samples (P = .009) and swine (P < .0001).

Resistance to zinc and cadmium was observed to be associated with MRSA, a finding consistently observed in European studies. Prolonged exposure to zinc in livestock feeds and fertilizers could propagate resistance to the metal ion, thereby hindering use of zinc-based topical agents in treating S. aureus infections.

To build and to begin evaluating a regional automated system to notify infection preventionists (IPs) when a patient with a history of gram-negative rod multidrug-resistant organism (GNRMDRO) is admitted to an emergency department (ED) or inpatient setting.

Observational, retrospective study.

Twenty-seven hospitals, mostly in the Indianapolis metropolitan area, in a health information exchange (HIE).

During testing of the new system: 80,180 patients with microbiology cultures between October 1, 2013, and December 31, 2013; 573 had a GNRMDRO.

A Health Level Seven (HL7) data feed from the HIE was obtained, corrected, enhanced, and used for decision support (secure e-mail notification to the IPs). Retrospective analysis of patients with microbiology data (October 1, 2013, through December 31, 2013) and subsequent healthcare encounters (through February 6, 2014).

The 573 patients (median age, 66 years; 68% women) had extended-spectrum β-lactamase-producing Enterobacteriaceae (78%), carbapenem-resistant Enterobacteriaceae (7%), Pseudomonas aeruginosa (9%), Acinetobacter baumannii (3%), or other GNR (3%). Body sources were urine (68%), sputum/trachea/bronchoalveolar lavage (13%), wound/skin (6%), blood (6%), or other/unidentified (7%). Between October 1, 2013, and February 6, 2014, 252 (44%) of 573 had an ED or inpatient encounter after the GNRMDRO culture, 47 (19% of 252) at an institution different from where the culture was drawn. During the first 7 weeks of actual alerts (January 29, 2014, through March 19, 2014), alerts were generated regarding 67 patients (19 of 67 admitted elsewhere from where the culture was drawn).

It proved challenging but ultimately feasible to create a regional microbiology-based alert system. Even in a few months, we observed substantial crossover between institutions. This system, if it contributes to timely isolation, may help reduce the spread of GNRMDROs.

To understand the prevalence of multidrug-resistant organism (MDRO) infections among nursing home (NH) residents and the potential for their spread between NHs and acute care hospitals (ACHs).

Descriptive analyses of MDRO infections among NH residents using all NH residents in the Long-Term Care Minimum Data Set (MDS) 3.0 between October 1, 2010 and December 31, 2011.

Analysis of MDS data revealed a very high volume of bidirectional patient flow between NHs and ACHs, indicating the need to study MDRO infections in NHs as well as in hospitals. A total of 4.24% of NH residents had an active MDRO diagnosis on at least 1 MDS assessment during the study period. This rate significantly varied by sex, age, urban/rural status, and state. Approximately 2% of NH discharges to ACHs involved a resident with an active diagnosis of infection due to MDROs. Conversely, 1.8% of NH admissions from an ACH involved a patient with an active diagnosis of infection due to MDROs. Among residents who acquired an MDRO infection during the study period, 57% became positive in the NH, 41% in the ACH, and 2% in other settings (eg, at a private home or apartment).

Even though NHs are the most likely setting where residents would acquire MDROs after admission to an NH (accounting for 57% of cases), a significant fraction of NH residents acquire MDRO infection at ACHs (41%). Thus, effective MDRO infection control for NH residents requires simultaneous, cooperative interventions among NHs and ACHs in the same community.

Antibiograms have effectively improved antibiotic prescribing in acute-care settings; however, their effectiveness in skilled nursing facilities (SNFs) is currently unknown.

To develop SNF-specific antibiograms and identify opportunities to improve antibiotic prescribing.

Cross-sectional and pretest-posttest study among residents of 3 Maryland SNFs.

Antibiograms were created using clinical culture data from a 6-month period in each SNF. We also used admission clinical culture data from the acute care facility primarily associated with each SNF for transferred residents. We manually collected all data from medical charts, and antibiograms were created using WHONET software. We then used a pretest-posttest study to evaluate the effectiveness of an antibiogram on changing antibiotic prescribing practices in a single SNF. Appropriate empirical antibiotic therapy was defined as an empirical antibiotic choice that sufficiently covered the infecting organism, considering antibiotic susceptibilities.

We reviewed 839 patient charts from SNF and acute care facilities. During the initial assessment period, 85% of initial antibiotic use in the SNFs was empirical, and thus only 15% of initial antibiotics were based on culture results. Fluoroquinolones were the most frequently used empirical antibiotics, accounting for 54.5% of initial prescribing instances. Among patients with available culture data, only 35% of empirical antibiotic prescribing was determined to be appropriate. In the single SNF in which we evaluated antibiogram effectiveness, prevalence of appropriate antibiotic prescribing increased from 32% to 45% after antibiogram implementation; however, this was not statistically significant (P = .32).

Implementation of antibiograms may be effective in improving empirical antibiotic prescribing in SNFs.

To describe the prevalence, characteristics, and appropriateness of systemic antibiotic use in assisted living (AL) and to conduct a preliminary quality improvement intervention trial to reduce inappropriate prescribing.

Pre-post study, with a 13-month intervention period.

Four AL communities.

All prescribers, all AL staff who communicate with prescribers, and all patients who had an infection during the baseline and intervention periods.

A standardized form for AL staff, an online education course and 5 practice briefs for prescribers, and monthly quality improvement meetings with AL staff.

Monthly inventory of all systemic antibiotic prescriptions; interviews with the prescriber, AL staff member, closest family member, and patient (when capable) regarding 85 antibiotic prescribing episodes (30 baseline, 55 intervention), with data review by an expert panel to determine prescribing appropriateness.

The mean number of systemic antibiotic prescriptions was 3.44 per 1,000 resident-days at baseline and 3.37 during the intervention, a nonsignificant change (P = .30). Few prescribers participated in online training. AL staff use of the standardized form gradually increased during the program. The proportion of prescriptions rated as probably inappropriate was 26% at baseline and 15% during the intervention, a nonsignificant trend (P = .25). Drug selection was largely appropriate during both time periods.

AL antibiotic prescribing rates appear to be approximately one-half those seen in nursing homes, with up to a quarter being potentially inappropriate. Interventions to improve prescribing must reach all physicians and staff and most likely will require long time periods to have the optimal effect.

Inappropriate antibiotic prescribing commonly occurs in pediatric outpatients with acute respiratory tract infections. Antimicrobial stewardship programs are recommended for use in the hospital, but less is known about whether and how they will work in the ambulatory setting. Following a successful cluster-randomized trial to improve prescribing for common acute respiratory tract infections using education plus audit and feedback in a large, pediatric primary care network, we sought to explore the perceptions of the intervention and antibiotic overuse among participating clinicians.

We conducted a qualitative study using semistructured interviews with 24 pediatricians from 6 primary care practices who participated in an outpatient antimicrobial stewardship intervention. All interviews were transcribed and analyzed using a modified grounded theory approach.

Deep skepticism of the audit and feedback reports emerged. Respondents ignored reports or expressed distrust about them. One respondent admitted to gaming behavior. When asked about antibiotic overuse, respondents recognized it as a problem, but they believed it was driven by the behaviors of nonpediatric physicians. Parent pressure for antibiotics was identified by all respondents as a major barrier to the more judicious use of antibiotics. Respondents reported that they sometimes “caved” to parent pressure for social reasons.

To improve the effectiveness and sustainability of outpatient antimicrobial stewardship, it is critical to boost the credibility of audit data, engage primary care pediatricians in recognizing that their behavior contributes to antibiotic overuse, and address parent pressure to prescribe antibiotics.

To compare practice patterns regarding the diagnosis and management of streptococcal pharyngitis across pediatric primary care practices.

Retrospective cohort study.

All encounters to 25 pediatric primary care practices sharing an electronic health record.

Streptococcal pharyngitis was defined by an International Classification of Diseases, Ninth Revision code for acute pharyngitis, positive laboratory test, antibiotic prescription, and absence of an alternative bacterial infection. Logistic regression models standardizing for patient-level characteristics were used to compare diagnosis, testing, and broad-spectrum antibiotic treatment for children with pharyngitis across practices. Fixed-effects models and likelihood ratio tests were conducted to analyze within-practice variation.

Of 399,793 acute encounters in 1 calendar year, there were 52,658 diagnoses of acute pharyngitis, including 12,445 diagnoses of streptococcal pharyngitis. After excluding encounters by patients with chronic conditions and standardizing for age, sex, insurance type, and race, there was significant variability across and within practices in the diagnosis and testing for streptococcal pharyngitis. Excluding patients with antibiotic allergies or prior antibiotic use, off-guideline antibiotic prescribing for confirmed group A streptococcal pharyngitis ranged from 1% to 33% across practices (P < .001). At the clinician level, 13 of 25 sites demonstrated significant within-practice variability in off-guideline antibiotic prescribing (P ≤ .05). Only 18 of the 222 clinicians in the network accounted for half of all off-guideline antibiotic prescribing.

Significant variability in the diagnosis and treatment of pharyngitis exists across and within pediatric practices, which cannot be explained by relevant clinical or demographic factors. Our data support clinician-targeted interventions to improve adherence to prescribing guidelines for this common condition.

To determine whether controlling the prescription of targeted antibiotics would translate to a measurable reduction in hospital-onset Clostridium difficile infection (CDI) rates.

A multicenter before-and-after intervention comparative study.

Ten medical centers in the greater New York region. Intervention group comprised of 6 facilities with early antimicrobial stewardship programs (ASPs). The 4 facilities without ASPs made up the nonintervention group.

Intervention facilities identified target antibiotics using case-control studies and implemented ASP-based strategies to control their use. Pre- and postintervention hospital-onset CDI rates and antibiotic consumption were compared for a 20-month period from June 2010 to January 2012. Antibiotic usage was compared using defined daily dose, days of therapy, and number of courses prescribed. Comparisons used bivariate and regression techniques.

Intervention facilities identified piperacillin/tazobactam, fluoroquinolones, or cefepime (odds ratio, 2.0-9.8 in CDI case patients compared with those without CDI) as intervention targets and selected several interventions (all included a component of audit and feedback). Varying degrees of success were observed in reducing antibiotic consumption over time. Total target antibiotic use significantly decreased (P < .05) when measured by days of therapy and number of courses but not by defined daily dose. Intravenous moxifloxacin and oral ciprofloxacin use showed significant reduction when measured by defined daily dose and days of therapy (P ≤ .01). Number of courses with all forms of these antibiotics was reduced (P ≤ .005). Intervention hospitals reported fewer hospital-onset CDI cases (2.8 rate point difference) compared with nonintervention hospitals; however, we were unable to show statistically significant decreases in aggregate hospital-onset CDI either between intervention and nonintervention groups or within the intervention group over time.

Although decreases in target antibiotic consumption did not translate into reductions of hospital-onset CDI in this study, many valuable lessons (including implementation strategies and antibiotic consumption measures) were learned. The findings can inform potential policy decisions regarding incorporating control of CDI and ASP as healthcare quality measures.

To examine regional variation in the use and appropriateness of indwelling urinary catheters and catheter-associated urinary tract infection (CAUTI).

Cross-sectional study.

US acute care hospitals.

Hospitals were divided into 4 regions according to the US Census Bureau. Baseline data on urinary catheter use, catheter appropriateness, and CAUTI were collected from participating units. The catheter utilization ratio was calculated by dividing the number of catheter-days by the number of patient-days. We used the National Healthcare Safety Network (NHSN) definition (number of CAUTIs per 1,000 catheter-days) and a population-based definition (number of CAUTIs per 10,000 patient-days) to calculate CAUTI rates. Logistic and Poisson regression models were used to assess regional differences.

Data on 434,207 catheter-days over 1,400,770 patient-days were collected from 1,101 units within 726 hospitals across 34 states. Overall catheter utilization was 31%. Catheter utilization was significantly higher in non-intensive care units (ICUs) in the West compared with non-ICUs in all other regions. Approximately 30%–40% of catheters in non-ICUs were placed without an appropriate indication. Catheter appropriateness was the lowest in the West. A total of 1,099 CAUTIs were observed (NHSN rate of 2.5 per 1,000 catheter-days and a population-based rate of 7.8 per 10,000 patient-days). The population-based CAUTI rate was highest in the West (8.9 CAUTIs per 10,000 patient-days) and was significantly higher compared with the Midwest, even after adjusting for hospital characteristics (P = .02).

Regional differences in catheter use, appropriateness, and CAUTI rates were detected across US hospitals.

Healthcare-associated pneumonia (HCAP) is an entity distinct from community-acquired pneumonia (CAP). HCAP has a higher case-fatality rate, due either to HCAP organisms or to the health status of HCAP patients. The contribution of HCAP criteria to case-fatality rate is unknown.

We conducted a retrospective review of adult patients admitted with a diagnosis of pneumonia from July 2007 through November 2011 to 491 US hospitals. HCAP was defined as having at least 1 of the following: prior hospitalization within 90 days, hemodialysis, admission from a skilled nursing facility, or immune suppression. We compared characteristics of patients with CAP and patients with HCAP and explored the contribution of HCAP criteria to case-fatality rate in a hierarchical generalized linear model.

Of 436,483 patients hospitalized with pneumonia, 149,963 (34.4%) had HCAP. Compared to CAP patients, HCAP patients were older, had more comorbidities, and were more likely to require intensive care unit (ICU) care. In-hospital case-fatality rate was higher among patients with HCAP, compared to those with CAP (11.1% vs 5.1%, P < .001). After adjustment for demographics, comorbidities, presence of other infections, early ICU admission, chronic and acute medications, early tests and therapies, and length of stay, HCAP remained associated with increased case-fatality rate (odds ratio [OR], 1.35 [95% confidence interval (CI), 1.32-1.39]); odds of death increased for each additional HCAP criterion (OR [95% CI]: 1 criterion, 1.27 [1.23-1.31], 2 criteria, 1.55 [1.49-1.62], and 3 or more criteria, 1.88 [1.72-2.06]).

After adjustment for differences in patient characteristics, HCAP was associated with greater case-fatality rate than CAP. This difference may be due to HCAP organisms or to HCAP criteria themselves.

To develop and field test an implementation assessment tool for assessing progress of hospital units in implementing improvements for the prevention of ventilator-associated pneumonia (VAP) in a two-state collaborative, including data on actions implemented by participating teams and contextual factors that may influence their efforts. Using the data collected, learn how implementation actions can be improved and analyze effects of implementation progress on outcome measures.

We developed the tool as an interview protocol that included quantitative and qualitative items addressing actions on the Comprehensive Unit-based Safety Program (CUSP) and clinical interventions for use in guiding data collection via telephone interviews.

We conducted interviews with leaders of improvement teams from units participating in the two-state VAP prevention initiative.

We collected data from 43 hospital units as they implemented actions for the VAP initiative and performed descriptive analyzes of the data with comparisons across the 2 states.

Early in the VAP prevention initiative, most units had made only moderate progress overall in using many of the CUSP actions known to support their improvement processes. For contextual factors, a relatively small number of barriers were found to have important negative effects on implementation progress (in particular, barriers related to workload and time issues). We modified coaching provided to the unit teams to reinforce training in weak spots that the interviews identified.

These assessments provided important new knowledge regarding the implementation science of quality improvement projects, including feedback during implementation, and give a better understanding of which factors most affect implementation.

International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes are increasingly used to identify healthcare-associated infections, often with insufficient evidence demonstrating validity of the codes used. Absent medical record verification, we sought to confirm a claims algorithm to identify surgical site infections (SSIs) by examining the presence of clinically expected SSI treatment.

We performed a retrospective cohort study, using private insurer claims data from persons less than 65 years old with ICD-9-CM procedure or Current Procedure Terminology (CPT-4) codes for anterior cruciate ligament (ACL) reconstruction from January 2004 through December 2010. SSIs occurring within 90 days after ACL reconstruction were identified by ICD-9-CM diagnosis codes. Antibiotic utilization, surgical treatment, and microbiology culture claims within 14 days of SSI codes were used as evidence to support the SSI diagnosis.

Of 40,702 procedures, 401 (1.0%) were complicated by SSI, 172 (0.4%) of which were specifically identified as septic arthritis. Most SSIs were associated with an inpatient admission (232/401 [58%]), and/or surgical procedure(s) for treatment (250/401 [62%]). Temporally associated antibiotics, surgical treatment procedures, and cultures were present for 84% (338/401), 61% (246/401), and 59% (238/401), respectively. Only 5.7% (23/401) of procedures coded for SSI after the procedure had no antibiotics, surgical treatments, or cultures within 14 days of the SSI claims.

More than 94% of patients identified by our claims algorithm as having an SSI received clinically expected treatment for infection, including antibiotics, surgical treatment, and culture, suggesting that this algorithm has very good positive predictive value. This method may facilitate retrospective SSI surveillance and comparison of SSI rates across facilities and providers.

To understand how structural and process elements may affect the risk for surgical site infections (SSIs) in the ambulatory surgery center (ASC) environment, the researchers employed a tool known as socio-technical probabilistic risk assessment (ST-PRA). ST-PRA is particularly helpful for estimating risks in outcomes that are very rare, such as the risk of SSI in ASCs.

Study objectives were to (1) identify the risk factors associated with SSIs resulting from procedures performed at ASCs and (2) design an intervention to mitigate the likelihood of SSIs for the most common risk factors that were identified by the ST-PRA for a particular surgical procedure.

ST-PRA was used to study the SSI risk in the ASC setting. Both quantitative and qualitative data sources were utilized, and sensitivity analysis was performed to ensure the robustness of the results.

The event entitled “fail to protect the patient effectively” accounted for 51.9% of SSIs in the ambulatory care setting. Critical components of this event included several failure risk points related to skin preparation, antibiotic administration, staff training, proper response to glove punctures during surgery, and adherence to surgical preparation rules related to the wearing of jewelry, watches, and artificial nails. Assuming a 75% reduction in noncompliance on any combination of 2 of these 5 components, the risk for an SSI decreased from 0.0044 to between 0.0027 and 0.0035.

An intervention that targeted the 5 major components of the major risk point was proposed, and its implications were discussed.