Skin Antisepsis before Surgical Fixation of Extremity Fractures.

BACKGROUND: Studies evaluating surgical-site infection have had conflicting results with respect to the use of alcohol solutions containing iodine povacrylex or chlorhexidine gluconate as skin antisepsis before surgery to repair a fractured limb (i.e., an extremity fracture). METHODS: In a cluster-randomized, crossover trial at 25 hospitals in the United States and Canada, we randomly assigned hospitals to use a solution of 0.7% iodine povacrylex in 74% isopropyl alcohol (iodine group) or 2% chlorhexidine gluconate in 70% isopropyl alcohol (chlorhexidine group) as preoperative antisepsis for surgical procedures to repair extremity fractures. Every 2 months, the hospitals alternated interventions. Separate populations of patients with either open or closed fractures were enrolled and included in the analysis. The primary outcome was surgical-site infection, which included superficial incisional infection within 30 days or deep incisional or organ-space infection within 90 days. The secondary outcome was unplanned reoperation for fracture-healing complications. RESULTS: A total of 6785 patients with a closed fracture and 1700 patients with an open fracture were included in the trial. In the closed-fracture population, surgical-site infection occurred in 77 patients (2.4%) in the iodine group and in 108 patients (3.3%) in the chlorhexidine group (odds ratio, 0.74; 95% confidence interval [CI], 0.55 to 1.00; P = 0.049). In the open-fracture population, surgical-site infection occurred in 54 patients (6.5%) in the iodine group and in 60 patients (7.3%) in the chlorhexidine group (odd ratio, 0.86; 95% CI, 0.58 to 1.27; P = 0.45). The frequencies of unplanned reoperation, 1-year outcomes, and serious adverse events were similar in the two groups. CONCLUSIONS: Among patients with closed extremity fractures, skin antisepsis with iodine povacrylex in alcohol resulted in fewer surgical-site infections than antisepsis with chlorhexidine gluconate in alcohol. In patients with open fractures, the results were similar in the two groups. (Funded by the Patient-Centered Outcomes Research Institute and the Canadian Institutes of Health Research; PREPARE ClinicalTrials.gov number, NCT03523962.).

Characterizing Patients Presenting on Hospital Admission With Central Line-Associated Bloodstream Infections: A Multicenter Study.

BACKGROUND: There are no systematic measures of central line-associated bloodstream infections (CLABSIs) in patients maintaining central venous catheters (CVCs) outside acute care hospitals. To clarify the burden of CLABSIs in these patients, we characterized patients with CLABSI present on hospital admission (POA). METHODS: Retrospective cross-sectional analysis of patients with CLABSI-POA in 3 health systems covering 11 hospitals across Maryland, Washington DC, and Missouri from November 2020 to October 2021. CLABSI-POA was defined using an adaptation of the acute care CLABSI definition. Patient demographics, clinical characteristics, and outcomes were collected via record review. Cox proportional hazard analysis was used to assess factors associated with the all-cause mortality rate within 30 days. RESULTS: A total of 461 patients were identified as having CLABSI-POA. CVCs were most commonly maintained in home infusion therapy (32.8%) or oncology clinics (31.2%). Enterobacterales were the most common etiologic agent (29.2%). Recurrent CLABSIs occurred in a quarter of patients (25%). Eleven percent of patients died during the hospital admission. Among patients with CLABSI-POA, mortality risk increased with age (hazard ratio vs age <20 years by age group: 20-44 years, 11.2 [95% confidence interval, 1.46-86.22]; 45-64 years, 20.88 [2.84-153.58]; ≥65 years, 22.50 [2.98-169.93]) and lack of insurance (2.46 [1.08-5.59]), and it decreased with CVC removal (0.57 [.39-.84]). CONCLUSIONS: CLABSI-POA is associated with significant in-hospital mortality risk. Surveillance is required to understand the burden of CLABSI in the community to identify targets for CLABSI prevention initiatives outside acute care settings.

Sample-to-Answer Detection of SARS-CoV-2 Viremia Using Thermally Responsive Alkane Partitions.

The diagnosis of bloodborne viral infections (viremia) is currently relegated to central laboratories because of the complex procedures required to detect viruses in blood samples. The development of point-of-care diagnostics for viremia would enable patients to receive a diagnosis and begin treatment immediately instead of waiting days for results. Point-of-care systems for viremia have been limited by the challenges of integrating multiple precise steps into a fully automated (i.e., sample-to-answer), compact, low-cost system. We recently reported the development of thermally responsive alkane partitions (TRAPs), which enable the complete automation of diagnostic assays with complex samples. Here we report the use of TRAPs for the sample-to-answer detection of viruses in blood using a low-cost portable device and easily manufacturable cassettes. Specifically, we demonstrate the detection of SARS-CoV-2 in spiked blood samples, and we show that our system detects viremia in COVID-19 patient samples with good agreement to conventional RT-qPCR. We anticipate that our sample-to-answer system can be used to rapidly diagnose SARS-CoV-2 viremia at the point of care, leading to better health outcomes for patients with severe COVID-19 disease, and that our system can be applied to the diagnosis of other life-threatening bloodborne viral diseases, including Hepatitis C and HIV.

The Next Generation: Mentoring and Diversity in the Antibacterial Resistance Leadership Group.

The Antibacterial Resistance Leadership Group (ARLG) Mentoring Program was established to develop and prepare the next generation of clinician-scientists for a career in antibacterial resistance research. The ARLG Diversity, Equity, and Inclusion Working Group partners with the Mentoring Committee to help ensure diversity and excellence in the clinician-scientist workforce of the future. To advance the field of antibacterial research while fostering inclusion and diversity, the Mentoring Program has developed a number of fellowships, awards, and programs, which are described in detail in this article.

Adherence to Antimicrobial Prophylaxis Guidelines for Elective Surgeries Across 825 US Hospitals, 2019-2020.

BACKGROUND: There are limited US data assessing adherence to surgical antimicrobial prophylaxis guidelines, particularly across a large, nationwide sample. Moreover, commonly prescribed inappropriate antimicrobial prophylaxis regimens remain unknown, hindering improvement initiatives. METHODS: We conducted a retrospective cohort study of adults who underwent elective craniotomy, hip replacement, knee replacement, spinal procedure, or hernia repair in 2019-2020 at hospitals in the PINC AI (Premier) Healthcare Database. We evaluated adherence of prophylaxis regimens, with respect to antimicrobial agents endorsed in the American Society of Health-System Pharmacist guidelines, accounting for patient antibiotic allergy and methicillin-resistant Staphylococcus aureus colonization status. We used multivariable logistic regression with random effects by hospital to evaluate associations between patient, procedural, and hospital characteristics and guideline adherence. RESULTS: Across 825 hospitals and 521 091 inpatient elective surgeries, 308 760 (59%) were adherent to prophylaxis guidelines. In adjusted analysis, adherence varied significantly by US Census division (adjusted OR [aOR] range: .61-1.61) and was significantly lower in 2020 compared with 2019 (aOR: .92; 95% CI: .91-.94; P < .001). The most common reason for nonadherence was unnecessary vancomycin use. In a post hoc analysis, controlling for patient age, comorbidities, other nephrotoxic agent use, and patient and procedure characteristics, patients receiving cefazolin plus vancomycin had 19% higher odds of acute kidney injury (AKI) compared with patients receiving cefazolin alone (aOR: 1.19; 95% CI: 1.11-1.27; P < .001). CONCLUSIONS: Adherence to antimicrobial prophylaxis guidelines remains suboptimal, largely driven by unnecessary vancomycin use, which may increase the risk of AKI. Adherence decreased in the first year of the COVID-19 pandemic.

Patterns, Predictors, and Intercenter Variability in Empiric Gram-Negative Antibiotic Use Across 928 United States Hospitals.

BACKGROUND: Empiric antibiotic use among hospitalized adults in the United States (US) is largely undescribed. Identifying factors associated with broad-spectrum empiric therapy may inform antibiotic stewardship interventions and facilitate benchmarking. METHODS: We performed a retrospective cohort study of adults discharged in 2019 from 928 hospitals in the Premier Healthcare Database. "Empiric" gram-negative antibiotics were defined by administration before day 3 of hospitalization. Multivariable logistic regression models with random effects by hospital were used to evaluate associations between patient and hospital characteristics and empiric receipt of broad-spectrum, compared to narrow-spectrum, gram-negative antibiotics. RESULTS: Of 8 017 740 hospitalized adults, 2 928 657 (37%) received empiric gram-negative antibiotics. Among 1 781 306 who received broad-spectrum therapy, 30% did not have a common infectious syndrome present on admission (pneumonia, urinary tract infection, sepsis, or bacteremia), surgery, or an intensive care unit stay in the empiric window. Holding other factors constant, males were 22% more likely (adjusted odds ratio [aOR], 1.22 [95% confidence interval, 1.22-1.23]), and all non-White racial groups 6%-13% less likely (aOR range, 0.87-0.94), to receive broad-spectrum therapy. There were significant prescribing differences by region, with the highest adjusted odds of broad-spectrum therapy in the US West South Central division. Even after model adjustment, there remained substantial interhospital variability: Among patients receiving empiric therapy, the probability of receiving broad-spectrum antibiotics varied as much as 34+ percentage points due solely to the admitting hospital (95% interval of probabilities: 43%-77%). CONCLUSIONS: Empiric gram-negative antibiotic use is highly variable across US regions, and there is high, unexplained interhospital variability. Sex and racial disparities in the receipt of broad-spectrum therapy warrant further investigation.

Is Carbapenem Therapy Necessary for the Treatment of Non-CTX-M ESBL-Producing Enterobacterales Bloodstream Infections?

BACKGROUND: Investigations into antibiotics for extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) bloodstream infections (BSIs) have focused on blaCTX-M genes. Outcomes of patients with non-CTX-M-producing ESBL-E BSIs and optimal treatment are unknown. METHODS: A multicenter observational study investigating 500 consecutive patients with ceftriaxone-resistant Enterobacterales BSIs during 2018-2022 was conducted. Broth microdilution and whole genome sequencing confirmed antibiotic susceptibilities and ESBL gene presence, respectively. Inverse probability weighting (IPW) using propensity scores was employed to ensure patients infected with non-CTX-M and CTX-M ESBL-E BSIs were similar prior to evaluation of outcomes. RESULTS: 396 patients (79.2%) were confirmed to have an ESBL-E BSI. ESBL gene family prevalence was as follows: blaCTX-M (n=370), blaSHV (n=16), blaOXY (n=12), and blaVEB (n=5). ESBL gene identification was not limited to Escherichia coli and Klebsiella species. In the IPW cohort, there was no difference in 30-day mortality or ESBL-E infection recurrence between the non-CTX-M and CTX-M groups (OR=.99, 95% CI 0.87-1.11; p=0.83) and (OR=1.10, 95% CI 0.85--1.42; p=0.47), respectively. In an exploratory analysis limited to the non-CTX-M group, 86% of the 21 patients receiving meropenem were alive on day 30; none of the 5 patients receiving piperacillin-tazobactam were alive on day 30. CONCLUSIONS: Our findings suggest that non-CTX-M and CTX-M ESBL-producing Enterobacterales BSIs are equally concerning and associated with similar clinical outcomes. Meropenem may be associated with improved survival in patients with non-CTX-M ESBL-E BSIs, underscoring the potential benefit of comprehensive molecular diagnostics to enable early antibiotic optimization for patients with ESBL-E BSI, beyond just blaCTX-M genes.

The Impact of Universal Glove and Gown Use on Clostridioides Difficile Acquisition: A Cluster-Randomized Trial.

BACKGROUND: Clostridioides difficile is the most common cause of healthcare-associated infections in the United States. It is unknown whether universal gown and glove use in intensive care units (ICUs) decreases acquisition of C. difficile. METHODS: This was a secondary analysis of a cluster-randomized trial in 20 medical and surgical ICUs in 20 US hospitals from 4 January 2012 to 4 October 2012. After a baseline period, ICUs were randomized to standard practice for glove and gown use versus the intervention of all healthcare workers being required to wear gloves and gowns for all patient contact and when entering any patient room (contact precautions). The primary outcome was acquisition of toxigenic C. difficile determined by surveillance cultures collected on admission and discharge from the ICU. RESULTS: A total of 21 845 patients had both admission and discharge perianal swabs cultured for toxigenic C. difficile. On admission, 9.43% (2060/21 845) of patients were colonized with toxigenic C. difficile. No significant difference was observed in the rate of toxigenic C. difficile acquisition with universal gown and glove use. Differences in acquisition rates in the study period compared with the baseline period in control ICUs were 1.49 per 100 patient-days versus 1.68 per 100 patient-days in universal gown and glove ICUs (rate difference, -0.28; generalized linear mixed model, P = .091). CONCLUSIONS: Glove and gown use for all patient contact in medical and surgical ICUs did not result in a reduction in the acquisition of C. difficile compared with usual care. CLINICAL TRIALS REGISTRATION: NCT01318213.

Active Surveillance and Contact Precautions for Preventing Methicillin-Resistant Staphylococcus aureus Healthcare-Associated Infections During the COVID-19 Pandemic.

BACKGROUND: Statistically significant decreases in methicillin-resistant Staphylococcus aureus (MRSA) healthcare-associated infections (HAIs) occurred in Veterans Affairs (VA) hospitals from 2007 to 2019 using a national policy of active surveillance (AS) for facility admissions and contact precautions for MRSA colonized (CPC) or infected (CPI) patients, but the impact of suspending these measures to free up laboratory resources for testing and conserve personal protective equipment for coronavirus disease 2019 (COVID-19) on MRSA HAI rates is not known. METHODS: From July 2020 to June 2022 all 123 acute care VA hospitals nationwide were given the rolling option to suspend (or re-initiate) any combination of AS, CPC, or CPI each month, and MRSA HAIs in intensive care units (ICUs) and non-ICUs were tracked. RESULTS: There were 917 591 admissions, 5 225 174 patient-days, and 568 MRSA HAIs. The MRSA HAI rate/1000 patient-days in ICUs was 0.20 (95% confidence interval [CI], .15-.26) for facilities practicing "AS + CPC + CPI" compared to 0.65 (95% CI, .41-.98; P < .001) for those not practicing any of these strategies, and in non-ICUs was 0.07 (95% CI, .05-.08) and 0.12 (95% CI, .08-.19; P = .01) for the respective policies. Accounting for monthly COVID-19 facility admissions using a negative binomial regression model did not change the relationships between facility policy and MRSA HAI rates. There was no significant difference in monthly facility urinary catheter-associated infection rates, a non-equivalent dependent variable, in the policy categories in either ICUs or non-ICUs. CONCLUSIONS: Facility removal of MRSA prevention practices was associated with higher rates of MRSA HAIs in ICUs and non-ICUs.

Prevalence of Acinetobacter baumannii and Candida auris in Patients Receiving Mechanical Ventilation.

Importance: To date, only 1 statewide prevalence survey has been performed for Acinetobacter baumannii (2009) in the US, and no statewide prevalence survey has been performed for Candida auris, making the current burden of these emerging pathogens unknown. Objective: To determine the prevalence of A baumannii and C auris among patients receiving mechanical ventilation in Maryland. Design, Setting, and Participants: The Maryland Multi-Drug Resistant Organism Prevention Collaborative performed a statewide cross-sectional point prevalence of patients receiving mechanical ventilation admitted to acute care hospitals (n = 33) and long-term care facilities (n = 18) between March 7, 2023, and June 8, 2023. Surveillance cultures (sputum, perianal, arm/leg, and axilla/groin) were obtained from all patients receiving mechanical ventilation. Sputum, perianal, and arm/leg cultures were tested for A baumannii and antibiotic susceptibility testing was performed. Axilla/groin cultures were tested by polymerase chain reaction for C auris. Main Outcomes and Measures: Prevalence of A baumannii, carbapenem-resistant A baumannii (CRAB), and C auris. Prevalence was stratified by type of facility. Results: All 51 eligible health care facilities (100%) participated in the survey. A total of 482 patients receiving mechanical ventilation were screened for A baumannii and 470 were screened for C auris. Among the 482 patients who had samples collected, 30.7% (148/482) grew A baumannii, 88 of the 148 (59.5%) of these A baumannii were CRAB, and C auris was identified in 31 of 470 (6.6%). Patients in long-term care facilities were more likely to be colonized with A baumannii (relative risk [RR], 7.66 [95% CI, 5.11-11.50], P < .001), CRAB (RR, 5.48 [95% CI, 3.38-8.91], P < .001), and C auris (RR, 1.97 [95% CI, 0.99-3.92], P = .05) compared with patients in acute care hospitals. Nine patients (29.0%) with cultures positive for C auris were previously unreported to the Maryland Department of Health. Conclusions: A baumannii, carbapenem-resistant A baumannii, and C auris were common among patients receiving mechanical ventilation in both acute care hospitals and long-term care facilities. Both pathogens were significantly more common in long-term care facilities than in acute care hospitals. Patients receiving mechanical ventilation in long-term care facilities are a high-risk population for emerging pathogens, and surveillance and prevention efforts should be targeted to these facilities.

Considerations for the Use of Phage Therapy in Clinical Practice.

Increasing antimicrobial resistance and medical device-related infections have led to a renewed interest in phage therapy as an alternative or adjunct to conventional antimicrobials. Expanded access and compassionate use cases have risen exponentially but have varied widely in approach, methodology, and clinical situations in which phage therapy might be considered. Large gaps in knowledge contribute to heterogeneity in approach and lack of consensus in many important clinical areas. The Antibacterial Resistance Leadership Group (ARLG) has convened a panel of experts in phage therapy, clinical microbiology, infectious diseases, and pharmacology, who worked with regulatory experts and a funding agency to identify questions based on a clinical framework and divided them into three themes: potential clinical situations in which phage therapy might be considered, laboratory testing, and pharmacokinetic considerations. Suggestions are provided as answers to a series of questions intended to inform clinicians considering experimental phage therapy for patients in their clinical practices.

Acquisition of Antibiotic-Resistant Gram-negative Bacteria in the Benefits of Universal Glove and Gown (BUGG) Cluster Randomized Trial.

BACKGROUND: The Benefits of Universal Glove and Gown (BUGG) cluster randomized trial found varying effects on methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus and no increase in adverse events. The aim of this study was to assess whether the intervention decreases the acquisition of antibiotic-resistant gram-negative bacteria. METHODS: This was a secondary analysis of a randomized trial in 20 hospital intensive care units. The intervention consisted of healthcare workers wearing gloves and gowns when entering any patient room compared to standard care. The primary composite outcome was acquisition of any antibiotic-resistant gram-negative bacteria based on surveillance cultures. RESULTS: A total of 40 492 admission and discharge perianal swabs from 20 246 individual patient admissions were included in the primary outcome. For the primary outcome of acquisition of any antibiotic-resistant gram-negative bacteria, the intervention had a rate ratio (RR) of 0.90 (95% confidence interval [CI], .71-1.12; P = .34). Effects on the secondary outcomes of individual bacteria acquisition were as follows: carbapenem-resistant Enterobacteriaceae (RR, 0.86 [95% CI, .60-1.24; P = .43), carbapenem-resistant Acinetobacter (RR, 0.81 [95% CI, .52-1.27; P = .36), carbapenem-resistant Pseudomonas (RR, 0.88 [95% CI, .55-1.42]; P = .62), and extended-spectrum ß-lactamase-producing bacteria (RR, 0.94 [95% CI, .71-1.24]; P = .67). CONCLUSIONS: Universal glove and gown use in the intensive care unit was associated with a non-statistically significant decrease in acquisition of antibiotic-resistant gram-negative bacteria. Individual hospitals should consider the intervention based on the importance of these organisms at their hospital, effect sizes, CIs, and cost of instituting the intervention. CLINICAL TRIALS REGISTRATION: NCT01318213.

Impact of Sex and Metabolic Comorbidities on Coronavirus Disease 2019 (COVID-19) Mortality Risk Across Age Groups: 66 646 Inpatients Across 613 U.S. Hospitals.

BACKGROUND: The relationship between common patient characteristics, such as sex and metabolic comorbidities, and mortality from coronavirus disease 2019 (COVID-19) remains incompletely understood. Emerging evidence suggests that metabolic risk factors may also vary by age. This study aimed to determine the association between common patient characteristics and mortality across age-groups among COVID-19 inpatients. METHODS: We performed a retrospective cohort study of patients discharged from hospitals in the Premier Healthcare Database between April-June 2020. Inpatients were identified using COVID-19 ICD-10-CM diagnosis codes. A priori-defined exposures were sex and present-on-admission hypertension, diabetes, obesity, and interactions between age and these comorbidities. Controlling for additional confounders, we evaluated relationships between these variables and in-hospital mortality in a log-binomial model. RESULTS: Among 66 646 (6.5%) admissions with a COVID-19 diagnosis, across 613 U.S. hospitals, 12 388 (18.6%) died in-hospital. In multivariable analysis, male sex was independently associated with 30% higher mortality risk (aRR, 1.30, 95% CI: 1.26-1.34). Diabetes without chronic complications was not a risk factor at any age (aRR 1.01, 95% CI: 0.96-1.06), and hypertension without chronic complications was a risk factor only in 20-39 year-olds (aRR, 1.68, 95% CI: 1.17-2.40). Diabetes with chronic complications, hypertension with chronic complications, and obesity were risk factors in most age-groups, with highest relative risks among 20-39 year-olds (respective aRRs 1.79, 2.33, 1.92; P-values ≤ .002). CONCLUSIONS: Hospitalized men with COVID-19 are at increased risk of death across all ages. Hypertension, diabetes with chronic complications, and obesity demonstrated age-dependent effects, with the highest relative risks among adults aged 20-39.

Significant Regional Differences in Antibiotic Use Across 576 US Hospitals and 11 701 326 Adult Admissions, 2016-2017.

BACKGROUND: Quantifying the amount and diversity of antibiotic use in United States hospitals assists antibiotic stewardship efforts but is hampered by limited national surveillance. Our study aimed to address this knowledge gap by examining adult antibiotic use across 576 hospitals and nearly 12 million encounters in 2016-2017. METHODS: We conducted a retrospective study of patients aged ≥ 18 years discharged from hospitals in the Premier Healthcare Database between 1 January 2016 and 31 December 2017. Using daily antibiotic charge data, we mapped antibiotics to mutually exclusive classes and to spectrum of activity categories. We evaluated relationships between facility and case-mix characteristics and antibiotic use in negative binomial regression models. RESULTS: The study included 11 701 326 admissions, totaling 64 064 632 patient-days, across 576 hospitals. Overall, patients received antibiotics in 65% of hospitalizations, at a crude rate of 870 days of therapy (DOT) per 1000 patient-days. By class, use was highest among ß-lactam/ß-lactamase inhibitor combinations, third- and fourth-generation cephalosporins, and glycopeptides. Teaching hospitals averaged lower rates of total antibiotic use than nonteaching hospitals (834 vs 957 DOT per 1000 patient-days; P < .001). In adjusted models, teaching hospitals remained associated with lower use of third- and fourth-generation cephalosporins and antipseudomonal agents (adjusted incidence rate ratio [95% confidence interval], 0.92 [.86-.97] and 0.91 [.85-.98], respectively). Significant regional differences in total and class-specific antibiotic use also persisted in adjusted models. CONCLUSIONS: Adult inpatient antibiotic use remains high, driven predominantly by broad-spectrum agents. Better understanding reasons for interhospital usage differences, including by region and teaching status, may inform efforts to reduce inappropriate antibiotic prescribing.

The Limited Utility of Ranking Hospitals Based on Their Colon Surgery Infection Rates.

BACKGROUND: The Centers for Medicare and Medicaid Services (CMS) use colon surgical site infection (SSI) rates to rank hospitals and apply financial penalties. The CMS' risk-adjustment model omits potentially impactful variables that might disadvantage hospitals with complex surgical populations. METHODS: We analyzed adult patients who underwent colon surgery within facilities associated with HCA Healthcare from 2014 to 2016. SSIs were identified from National Health Safety Network (NHSN) reporting. We trained and validated 3 SSI prediction models, using (1) current CMS model variables, including hospital-specific random effects (HCA-adapted CMS model); (2) demographics and claims-based comorbidities (expanded-claims model); and (3) demographics, claims-based comorbidities, and NHSN variables (claims-plus-electronic health record [EHR] model). Discrimination, calibration, and resulting rankings were compared among all models and the current CMS model with published coefficient values. RESULTS: We identified 39 468 colon surgeries in 149 hospitals, resulting in 1216 (3.1%) SSIs. Compared to the HCA-adapted CMS model, the expanded-claims model had similar performance (c-statistic, 0.65 vs 0.67, respectively), while the claims-plus-EHR model was more accurate (c-statistic, 0.70; 95% confidence interval, .67-.73; P = .004). The sampling variation, due to the low surgical volume and small number of infections, contributed 74% of the total variation in observed SSI rates between hospitals. When CMS model rankings were compared to those from the expanded-claims and claims-plus-EHR models, 18 (15%) and 26 (22%) hospitals changed quartiles, respectively, and 10 (8.3%) and 12 (10%) hospitals changed into or out of the lowest-performing quartile, respectively. CONCLUSIONS: An expanded set of variables improved colon SSI risk predictions and quartile assignments, but low procedure volumes and SSI events remain a barrier to effectively comparing hospitals.

A Multicenter Evaluation of Probiotic Use for the Primary Prevention of Clostridioides difficile Infection.

BACKGROUND: Primary prevention of Clostridioides difficile infection (CDI) is a priority for hospitals. Probiotics have the potential to interfere with colonization and CDI. In this study, we evaluated the impact of a computerized clinical decision support (CCDS) tool to prescribe probiotics for primary prevention of CDI among adult hospitalized patients. METHODS: A CCDS tool was implemented into the electronic medical record at 4 hospitals to prompt prescription of a probiotic preparation at the time of antibiotic prescription in high-risk patients in May 2019. Interrupted time series using segmented regression analysis was conducted to evaluate hospital-wide CDI incidence for the year pre- and post-CCDS implementation. In addition, multivariable logistic regression was used to evaluate CDI incidence in patients who qualified for probiotics in the pre- vs post-intervention periods, adjusting for potential confounders. To adjust for potential differences in patients who received probiotics in the post-intervention period, propensity score-matched pairs were developed to evaluate CDI risk by receipt of probiotics. RESULTS: Quarterly CDI incidence increased over time post-intervention relative to baseline trends (slope change, 1.4; 95% confidence interval [CI], .9-1.9). The odds ratio (OR) of CDI was 1.41 in eligible patients post-intervention compared with pre-intervention (adjusted OR, 1.41; 95% CI, 1.11-1.79). Propensity score-matched analysis showed that patients who received probiotics did not have lower rates of CDI compared with those who did not receive probiotics (OR, 1.46; 95% CI, .87-2.45). CONCLUSIONS: Use of probiotics for primary prevention of CDI among adult inpatients receiving antibiotics is not supported.

Electronically Available Patient Claims Data Improve Models for Comparing Antibiotic Use Across Hospitals: Results From 576 US Facilities.

BACKGROUND: The Centers for Disease Control and Prevention (CDC) uses standardized antimicrobial administration ratios (SAARs)-that is, observed-to-predicted ratios-to compare antibiotic use across facilities. CDC models adjust for facility characteristics when predicting antibiotic use but do not include patient diagnoses and comorbidities that may also affect utilization. This study aimed to identify comorbidities causally related to appropriate antibiotic use and to compare models that include these comorbidities and other patient-level claims variables to a facility model for risk-adjusting inpatient antibiotic utilization. METHODS: The study included adults discharged from Premier Database hospitals in 2016-2017. For each admission, we extracted facility, claims, and antibiotic data. We evaluated 7 models to predict an admission's antibiotic days of therapy (DOTs): a CDC facility model, models that added patient clinical constructs in varying layers of complexity, and an external validation of a published patient-variable model. We calculated hospital-specific SAARs to quantify effects on hospital rankings. Separately, we used Delphi Consensus methodology to identify Elixhauser comorbidities associated with appropriate antibiotic use. RESULTS: The study included 11 701 326 admissions across 576 hospitals. Compared to a CDC-facility model, a model that added Delphi-selected comorbidities and a bacterial infection indicator was more accurate for all antibiotic outcomes. For total antibiotic use, it was 24% more accurate (respective mean absolute errors: 3.11 vs 2.35 DOTs), resulting in 31-33% more hospitals moving into bottom or top usage quartiles postadjustment. CONCLUSIONS: Adding electronically available patient claims data to facility models consistently improved antibiotic utilization predictions and yielded substantial movement in hospitals' utilization rankings.

Antibacterial Resistance Leadership Group 2.0: Back to Business.

In December 2019, the Antibacterial Resistance Leadership Group (ARLG) was awarded funding for another 7-year cycle to support a clinical research network on antibacterial resistance. ARLG 2.0 has 3 overarching research priorities: infections caused by antibiotic-resistant (AR) gram-negative bacteria, infections caused by AR gram-positive bacteria, and diagnostic tests to optimize use of antibiotics. To support the next generation of AR researchers, the ARLG offers 3 mentoring opportunities: the ARLG Fellowship, Early Stage Investigator seed grants, and the Trialists in Training Program. The purpose of this article is to update the scientific community on the progress made in the original funding period and to encourage submission of clinical research that addresses 1 or more of the research priority areas of ARLG 2.0.

Antibiotic Use and Bacterial Infection among Inpatients in the First Wave of COVID-19: a Retrospective Cohort Study of 64,691 Patients.

Hospitalized patients with SARS-CoV-2 infection (COVID-19) often receive antibiotics for suspected bacterial coinfection. We estimated the incidence of bacterial coinfection and secondary infection in COVID-19 using clinical diagnoses to determine how frequently antibiotics are administered when bacterial infection is absent. We performed a retrospective cohort study of inpatients with COVID-19 present on admission to hospitals in the Premier Healthcare Database between April and June 2020. Bacterial infections were defined using ICD-10-CM diagnosis codes and associated "present on admission" coding. Coinfections were defined by bacterial infection present on admission, while secondary infections were defined by bacterial infection that developed after admission. Coinfection and secondary infection were not mutually exclusive. A total of 18.5% of 64,961 COVID-19 patients (n = 12,040) presented with bacterial infection at admission, 3.8% (n = 2,506) developed secondary infection after admission, and 0.9% (n = 574) had both; 76.3% (n = 49,551) received an antibiotic while hospitalized, including 71% of patients who had no diagnosis of bacterial infection. Secondary bacterial infection occurred in 5.7% of patients receiving steroids in the first 2 days of hospitalization, 9.9% receiving tocilizumab in the first 2 days of hospitalization, and 10.3% of patients receiving both. After adjusting for patient and hospital characteristics, bacterial coinfection (adjusted relative risk [aRR], 1.15; 95% confidence interval [CI], 1.11 to 1.20) and secondary infection (aRR 1.93; 95% CI, 1.82 to 2.04) were both independently associated with increased mortality. Although 1 in 5 inpatients with COVID-19 presents with bacterial infection, secondary infections in the hospital are uncommon. Most inpatients with COVID-19 receive antibiotic therapy, including 71% of those not diagnosed with bacterial infection.

Comparing Propensity Score Methods Versus Traditional Regression Analysis for the Evaluation of Observational Data: A Case Study Evaluating the Treatment of Gram-Negative Bloodstream Infections.

BACKGROUND: Propensity score methods are increasingly being used in the infectious diseases literature to estimate causal effects from observational data. However, there remains a general gap in understanding among clinicians on how to critically review observational studies that have incorporated these analytic techniques. METHODS: Using a cohort of 4967 unique patients with Enterobacterales bloodstream infections, we sought to answer the question "Does transitioning patients with gram-negative bloodstream infections from intravenous to oral therapy impact 30-day mortality?" We conducted separate analyses using traditional multivariable logistic regression, propensity score matching, propensity score inverse probability of treatment weighting, and propensity score stratification using this clinical question as a case study to guide the reader through (1) the pros and cons of each approach, (2) the general steps of each approach, and (3) the interpretation of the results of each approach. RESULTS: 2161 patients met eligibility criteria with 876 (41%) transitioned to oral therapy while 1285 (59%) remained on intravenous therapy. After repeating the analysis using the 4 aforementioned methods, we found that the odds ratios were broadly similar, ranging from 0.84-0.95. However, there were some relevant differences between the interpretations of the findings of each approach. CONCLUSIONS: Propensity score analysis is overall a more favorable approach than traditional regression analysis when estimating causal effects using observational data. However, as with all analytic methods using observational data, residual confounding will remain; only variables that are measured can be accounted for. Moreover, propensity score analysis does not compensate for poor study design or questionable data accuracy.