Intra-abdominal infections survival guide: a position statement by the Global Alliance For Infections In Surgery.

Intra-abdominal infections (IAIs) are an important cause of morbidity and mortality in hospital settings worldwide. The cornerstones of IAI management include rapid, accurate diagnostics; timely, adequate source control; appropriate, short-duration antimicrobial therapy administered according to the principles of pharmacokinetics/pharmacodynamics and antimicrobial stewardship; and hemodynamic and organ functional support with intravenous fluid and adjunctive vasopressor agents for critical illness (sepsis/organ dysfunction or septic shock after correction of hypovolemia). In patients with IAIs, a personalized approach is crucial to optimize outcomes and should be based on multiple aspects that require careful clinical assessment. The anatomic extent of infection, the presumed pathogens involved and risk factors for antimicrobial resistance, the origin and extent of the infection, the patient's clinical condition, and the host's immune status should be assessed continuously to optimize the management of patients with complicated IAIs.

The prevalence of gram-negative bacteria with difficult-to-treat resistance and utilization of novel ß-lactam antibiotics in the southeastern United States.

Objective: To evaluate temporal trends in the prevalence of gram-negative bacteria (GNB) with difficult-to-treat resistance (DTR) in the southeastern United States. Secondary objective was to examine the use of novel ß-lactams for GNB with DTR by both antimicrobial use (AU) and a novel metric of adjusted AU by microbiological burden (am-AU). Design: Retrospective, multicenter, cohort. Setting: Ten hospitals in the southeastern United States. Methods: GNB with DTR including Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter spp. from 2015 to 2020 were tracked at each institution. Cumulative AU of novel ß-lactams including ceftolozane/tazobactam, ceftazidime/avibactam, meropenem/vaborbactam, imipenem/cilastatin/relebactam, and cefiderocol in days of therapy (DOT) per 1,000 patient-days was calculated. Linear regression was utilized to examine temporal trends in the prevalence of GNB with DTR and cumulative AU of novel ß-lactams. Results: The overall prevalence of GNB with DTR was 0.85% (1,223/143,638) with numerical increase from 0.77% to 1.00% between 2015 and 2020 (P = .06). There was a statistically significant increase in DTR Enterobacterales (0.11% to 0.28%, P = .023) and DTR Acinetobacter spp. (4.2% to 18.8%, P = .002). Cumulative AU of novel ß-lactams was 1.91 ± 1.95 DOT per 1,000 patient-days. When comparing cumulative mean AU and am-AU, there was an increase from 1.91 to 2.36 DOT/1,000 patient-days, with more than half of the hospitals shifting in ranking after adjustment for microbiological burden. Conclusions: The overall prevalence of GNB with DTR and the use of novel ß-lactams remain low. However, the uptrend in the use of novel ß-lactams after adjusting for microbiological burden suggests a higher utilization relative to the prevalence of GNB with DTR.

Incidence and predictors of complications in Gram-negative bloodstream infection.

BACKGROUND: The incidence of metastatic complications in Gram-negative bloodstream infection (GN-BSI) remains undefined. This retrospective cohort study examines the incidence and predictors of complications within 90 days of GN-BSI. METHODS: Patients with GN-BSIs hospitalized at two Prisma Health-Midlands hospitals in Columbia, South Carolina, USA from 1 January 2012 through 30 June 2015 were included. Complications of GN-BSI included endocarditis, septic arthritis, osteomyelitis, spinal infections, deep-seated abscesses, and recurrent GN-BSI. Kaplan-Meier analysis and multivariate Cox proportional hazards regression were used to examine incidence and risk factors of complications, respectively. RESULTS: Among 752 patients with GN-BSI, median age was 66 years and 380 (50.5%) were women. The urinary tract was the most common source of GN-BSI (378; 50.3%) and Escherichia coli was the most common bacteria (375; 49.9%). Overall, 13.9% of patients developed complications within 90 days of GN-BSI. The median time to identification of these complications was 5.2 days from initial GN-BSI. Independent risk factors for complications were presence of indwelling prosthetic material (hazards ratio [HR] 1.73, 95% confidence intervals [CI] 1.08-2.78), injection drug use (HR 6.84, 95% CI 1.63-28.74), non-urinary source (HR 1.98, 95% CI 1.18-3.23), BSI due to S. marcescens, P. mirabilis or P. aeruginosa (HR 1.78, 95% CI 1.05-3.03), early clinical failure criteria (HR 1.19 per point, 95% CI 1.03-1.36), and persistent GN-BSI (HR 2.97, 95% CI 1.26-6.99). CONCLUSIONS: Complications of GN-BSI are relatively common and may be predicted based on initial clinical response to antimicrobial therapy, follow-up blood culture results, and other host and microbiological factors.

Ecologic analysis of antimicrobial use in South Carolina hospitals during 2020-2022.

Background: Factors influencing excessive antimicrobial utilization in hospitalized patients remain poorly understood, particularly with the COVID-19 pandemic. Methods: In this retrospective cohort, we compared administrative data regarding antimicrobial prescriptions in hospitalized patients in South Carolina from March 2020 through September 2022. The study examined variables associated with antimicrobial use across demographics, COVID status, and length of stay, among other variables. Results: Significant relationships were seen with antimicrobial use in COVID-19 positive patients (OR 2.00, 95% Confidence Interval (CI): 1.9-2.1), young adults (OR 1.08, 95% CI: 0.99-1.12, COVID-19 positive Blacks and Hispanics (OR 1.06, 95% CI: 1.01-1.11, OR 1.05, 95% CI: 0.89-1.23), and COVID-19 positive patients with ≥2 comorbid conditions (OR 1.55, 95% CI: 1.43-1.68). Discussion: Further analysis in more than one healthcare system should explore these ecologic relationships further to understand if these are common trends to inform ongoing stewardship interventions.

Application of Precision Medicine Concepts in Ambulatory Antibiotic Management of Acute Pyelonephritis.

Acute pyelonephritis (APN) is a relatively common community-acquired infection, particularly in women. The early appropriate antibiotic treatment of this potentially life-threatening infection is associated with improved outcomes. The international management guidelines for complicated urinary tract infections and APN recommend using oral antibiotics with <10% resistance among urinary pathogens. However, increasing antibiotic resistance rates among Escherichia coli and other Enterobacterales to fluoroquinolones, trimethoprim-sulfamethoxazole (TMP-SMX), and beta-lactams has left patients without reliable oral antibiotic treatment options for APN. This narrative review proposes using precision medicine concepts to improve empirical antibiotic therapy for APN in ambulatory settings. Whereas resistance rates to a particular antibiotic class may exceed 10% at the population-based level, the predicted antibiotic resistance rates based on patient-specific risk factors fall under 10% in many patients with APN on the individual level. The utilization of clinical tools for the prediction of fluoroquinolones, TMP-SMX, and third-generation cephalosporin resistance improves the ambulatory antibiotic management of APN. It may also reduce the need to switch antibiotic therapy later based on the in vitro antibiotic susceptibility testing results of bacterial isolates in urinary cultures. This approach may mitigate the burden of increasing antibiotic resistance in the community by ensuring that the initial antibiotic prescribed has the highest likelihood of treating APN appropriately.

Intravenous versus Partial Oral Antibiotic Therapy in the Treatment of Uncomplicated Bloodstream Infection Due to Streptococcus Species.

This retrospective cohort study examines effectiveness of partial oral antibiotic regimens in uncomplicated bloodstream infections (BSIs) due to Streptococcus species compared to standard intravenous therapy. Adult patients with uncomplicated streptococcal BSIs from April 2016 to June 2020 in seven hospitals in South Carolina, USA, were evaluated. Multivariate Cox proportional hazards regression was used to examine the time to treatment failure within 90 days of a BSI after adjustment for the propensity to receive partial oral therapy. Multivariate linear regression was used to examine the hospital length of stay (HLOS). Among the 222 patients included, 99 received standard intravenous antibiotics and 123 received partial oral therapy. Of the standard intravenous therapy group, 46/99 (46.5%) required outpatient parenteral antibiotic therapy (OPAT). There was no difference in the risk of treatment failure between partial oral and standard intravenous therapy (hazards ratio 0.53, 95% CI 0.18, 1.60; p = 0.25). Partial oral therapy was independently associated with a shorter HLOS after adjustments for the propensity to receive partial oral therapy and other potential confounders (-2.23 days, 95% CI -3.53, -0.94; p < 0.001). Transitioning patients to oral antibiotics may be a reasonable strategy in the management of uncomplicated streptococcal BSIs. Partial oral therapy does not seem to have a higher risk of treatment failure and may spare patients from prolonged hospitalizations and OPAT complications.

Optimization of Empirical Antimicrobial Therapy in Enterobacterales Bloodstream Infection Using the Extended-Spectrum Beta-Lactamase Prediction Score.

Clinical tools for the prediction of antimicrobial resistance have been derived and validated without examination of their implementation in clinical practice. This study examined the impact of utilization of the extended-spectrum beta-lactamase (ESBL) prediction score on the time to initiation of appropriate antimicrobial therapy for bloodstream infection (BSI). The quasi-experimental cohort study included hospitalized adults with BSI due to ceftriaxone-resistant (CRO-R) Enterobacterales at three community hospitals in Columbia, South Carolina, USA before (January 2010 to December 2013) and after (January 2014 to December 2019) implementation of an antimicrobial stewardship intervention. In total, 45 and 101 patients with BSI due to CRO-R Enterobacterales were included before and after the intervention, respectively. Overall, the median age was 66 years, 85 (58%) were men, and 86 (59%) had a urinary source of infection. The mean time to appropriate antimicrobial therapy was 78 h before and 46 h after implementation of the antimicrobial stewardship intervention (p = 0.04). Application of the ESBL prediction score as part of an antimicrobial stewardship intervention was associated with a significant reduction in time to appropriate antimicrobial therapy in patients with BSI due to CRO-R Enterobacterales. Utilization of advanced rapid diagnostics may be necessary for a further reduction in time to appropriate antimicrobial therapy in this population.

Epidemiology, Outcomes and Tolerability of Protracted Treatment of Nontuberculous Mycobacterial Infections at a Community Teaching Hospital in the Southeastern United States.

Nontuberculous mycobacterial (NTM) infections present a treatment challenge for clinicians and patients. There are limited data about current susceptibility patterns and treatment outcomes in U.S. adults. This was a 10-year, single-center, retrospective, observational cohort study of adults with a positive NTM culture and clinical suspicion of infection between 1 January 2010 and 30 June 2020. The primary objective was to identify predictors for favorable treatment outcomes. Key secondary objectives were characterization of NTM epidemiology, susceptibility profiles, and safety and tolerability of treatment, including the proportion of subjects with an antimicrobial change and the reasons for the change. Of 250 subjects diagnosed with NTM infection, the most prevalent NTM isolates were Mycobacterium avium intracellulare complex (66.8%) followed by Mycobacterium abscessus (17.6%). Antimicrobial susceptibility data were available for 52.4% of the cohort (45.8% slow growers; 54.2% rapid growers). Only 88 (35%) subjects received treatment with evaluable clinical outcomes. The proportion of subjects with a favorable outcome was 61.4%. More subjects in the unfavorable outcome group experienced a change in antimicrobial therapy (73.5% vs. 51.9%, p = 0.043). The most common reason for antimicrobial change was adverse drug events (n = 36, 67.9%). In the regression model, private insurance was associated with a favorable outcome, whereas having multiple antimicrobial changes was associated with an unfavorable outcome. The complexity of NTM treatment and high incidence of medication-related issues suggest the necessity of interdisciplinary collaboration to improve overall treatment outcomes in NTM infections.

Candida parapsilosis bloodstream infection in an immunocompromised host with discordant multiplex polymerase chain reaction and conventional blood culture results: a case report.

Prompt treatment of candidemia, especially in immunocompromised hosts, is known to improve outcomes. We present a case of discordance among results of Gram stain, multiplex polymerase chain reaction (PCR)-based rapid diagnostic technology, and conventional cultures that subsequently resulted in delayed therapy and hospitalization. An immunocompromised patient presented to the outpatient oncology clinic with signs and symptoms of systemic infection. Blood cultures were obtained, and Gram stain showed gram-negative rods, while multiplex PCR results (BioFire® FilmArray® BCID 1) returned positive for both Enterobacter cloacae and Candida parapsilosis. Conventional cultures only grew E. cloacae. Because of the discordant results, the primary team elected to give ertapenem monotherapy and defer antifungal therapy. The patient's symptoms progressed, and 11 days later, the patient was admitted with subsequent positive blood cultures for C. parapsilosis. The patient required a 9-day hospitalization due to complications associated with candidemia. This case highlights the value of understanding and interpretation of rapid diagnostics, shared decision-making in antimicrobial management of high-risk patients, and the important responsibility of antimicrobial stewardship teams across the continuum of care.

Temporal Association between Influenza Vaccination Coverage and Ambulatory Antibiotic Use in Children.

In this population-based retrospective cohort study, increased influenza vaccination coverage was temporally associated with a reduction in ambulatory antibiotic use in children. After adjustment for yearly vaccine effectiveness, antibiotic prescription rate declined by 3/1000 person-months for each 1% increase in influenza vaccination coverage between 2012 and 2017 in South Carolina (P < 0.001).

It is time to define an organizational model for the prevention and management of infections along the surgical pathway: a worldwide cross-sectional survey.

BACKGROUND: The objectives of the study were to investigate the organizational characteristics of acute care facilities worldwide in preventing and managing infections in surgery; assess participants' perception regarding infection prevention and control (IPC) measures, antibiotic prescribing practices, and source control; describe awareness about the global burden of antimicrobial resistance (AMR) and IPC measures; and determine the role of the Coronavirus Disease 2019 pandemic on said awareness. METHODS: A cross-sectional web-based survey was conducted contacting 1432 health care workers (HCWs) belonging to a mailing list provided by the Global Alliance for Infections in Surgery. The self-administered questionnaire was developed by a multidisciplinary team. The survey was open from May 22, 2021, and June 22, 2021. Three reminders were sent, after 7, 14, and 21 days. RESULTS: Three hundred four respondents from 72 countries returned a questionnaire, with an overall response rate of 21.2%. Respectively, 90.4% and 68.8% of participants stated their hospital had a multidisciplinary IPC team or a multidisciplinary antimicrobial stewardship team. Local protocols for antimicrobial therapy of surgical infections and protocols for surgical antibiotic prophylaxis were present in 76.6% and 90.8% of hospitals, respectively. In 23.4% and 24.0% of hospitals no surveillance systems for surgical site infections and no monitoring systems of used antimicrobials were implemented. Patient and family involvement in IPC management was considered to be slightly or not important in their hospital by the majority of respondents (65.1%). Awareness of the global burden of AMR among HCWs was considered very important or important by 54.6% of participants. The COVID-19 pandemic was considered by 80.3% of respondents as a very important or important factor in raising HCWs awareness of the IPC programs in their hospital. Based on the survey results, the authors developed 15 statements for several questions regarding the prevention and management of infections in surgery. The statements may be the starting point for designing future evidence-based recommendations. CONCLUSION: Adequacy of prevention and management of infections in acute care facilities depends on HCWs behaviours and on the organizational characteristics of acute health care facilities to support best practices and promote behavioural change. Patient involvement in the implementation of IPC is still little considered. A debate on how operationalising a fundamental change to IPC, from being solely the HCWs responsibility to one that involves a collaborative relationship between HCWs and patients, should be opened.

Evaluation of early clinical failure criteria in Enterococcus species bloodstream infection.

PURPOSE: Early clinical failure criteria (ECFC) were recently introduced to predict unfavorable outcomes in patients with Gram-negative bloodstream infections (BSI). ECFC include hypotension, tachycardia, tachypnea or mechanical ventilation, altered mental status, and leukocytosis evaluated at 72-96 h after BSI. The aim of this retrospective cohort study was to assess performance of ECFC in predicting 28-day mortality in Enterococcus species BSI. METHODS: Hospitalized adults with Enterococcus species BSI at Prisma Health hospitals from 1 January 2015 to 31 July 2018 were identified. Multivariate logistic regression was used to determine the association between ECFC and 28-day mortality. Area under the receiver operating characteristic (AUROC) curve was used to measure model discrimination. RESULTS: Among 157 patients, 28 (18%) died within 28 days of BSI. After adjustments in multivariate model, the risk of 28-day mortality increased in the presence of each additional ECFC (OR 1.6, 95% CI 1.2-2.3, p = 0.005). Infective endocarditis (OR 3.9, 95% CI 1.4-10.7, p = 0.01) was independently associated with 28-day mortality. AUROC curve of ECFC model in predicting 28-day mortality was 0.74 with ECFC of 2 identified as the best breakpoint. Mortality was 8% in patients with ECFC < 2 compared to 33% in those with ECFC ≥ 2 (p < 0.001). CONCLUSION: ECFC had good discrimination in predicting 28-day mortality in patients with Enterococcus species BSI. These criteria may have utility in future clinical investigations.

Prediction of mortality in Staphylococcus aureus bloodstream infection using quick Pitt bacteremia score.

OBJECTIVES: The quick Pitt bacteremia score (qPitt) predicts mortality in patients with serious infections due to gram-negative bacteria. This retrospective cohort study examines utility of qPitt to predict mortality in patients with Staphylococcus aureus bloodstream infection (SAB). METHODS: Multivariate logistic regression was used to examine risk factors for 28-day mortality in hospitalized adults with SAB at four Prisma Health hospitals in South Carolina, USA from January 2015 to December 2017. Area under receiver operating characteristic curve (AUROC) was used to examine model discrimination. RESULTS: Among 692 patients with SAB, 305 (44%) had methicillin-resistant S. aureus (MRSA), and 129 (19%) died within 28 days. After adjustment for age, comorbidities, and MRSA, each component of the qPitt was associated with 28-day mortality. There was a 3-fold increase in the risk of 28-day mortality for each one-point increase in qPitt. Predicted 28-day mortality was 3%, 9%, 22%, 45%, and 70% for qPitt of 0, 1, 2, 3, and ≥4, respectively. AUROC of the qPitt in predicting 28-day, 14-day, and in-hospital mortality were 0.80, 0.81, and 0.80, respectively. CONCLUSIONS: The qPitt predicts mortality with good discrimination in SAB. These results support using qPitt as a measure of acute severity of illness in future studies.

Change in Antimicrobial Use During COVID-19 Pandemic in South Carolina Hospitals: A Multicenter Observational Cohort Study.

OBJECTIVES: This retrospective cohort study examined the impact of the pandemic on antimicrobial use (AU) in South Carolina hospitals. METHODS: Antimicrobial use in days of therapy (DOT) per 1000 days-present was evaluated in 17 hospitals in South Carolina. Matched-pairs mean difference was used to compare AU during the pandemic (March-June 2020) with that during the same months in 2019 in hospitals that did and did not admit patients with COVID-19. RESULTS: There was a 6.6% increase in overall AU in the seven hospitals that admitted patients with COVID-19 (from 530.9 to 565.8; mean difference (MD) 34.9 DOT/1000 days-present; 95% CI 4.3, 65.6; P = 0.03). There was no significant change in overall AU in the remaining 10 hospitals that did not admit patients with COVID-19 (MD 6.0 DOT/1000 days-present; 95% CI -55.5, 67.6; P = 0.83). Most of the increase in AU in the seven hospitals that admitted patients with COVID-19 was observed in broad-spectrum antimicrobial agents. A 16.4% increase was observed in agents predominantly used for hospital-onset infections (from 122.3 to 142.5; MD 20.1 DOT/1000 days-present; 95% CI 11.1, 29.1; P = 0.002). There was also a 9.9% increase in the use of anti-methicillin-resistant Staphylococcus aureus (MRSA) agents (from 66.7 to 73.3; MD 6.6 DOT/1000 days-present; 95% CI 2.3, 10.8; P = 0.01). CONCLUSION: The COVID-19 pandemic appears to drive overall and broad-spectrum antimicrobial use in South Carolina hospitals admitting patients with COVID-19. Additional antimicrobial stewardship resources are needed to curtail excessive antimicrobial use in hospitals to prevent subsequent increases in antimicrobial resistance and Clostridioides difficile infection rates, given the continuing nature of the pandemic.

Impact of follow up blood cultures on outcomes of patients with community-onset gram-negative bloodstream infection.

BACKGROUND: The role of follow up blood cultures (FUBC) in the management of gram-negative bloodstream infection (GN-BSI) remains controversial. This retrospective cohort study examines the association between obtaining FUBC and mortality in GN-BSI. METHODS: Hospitalized adults with community-onset GN-BSI at Prisma Health-Midlands hospitals in South Carolina, USA from January 1, 2010 to June 30, 2015 were identified. Patients who died or were discharged from hospital within 72 h were excluded to minimize impact of survival and selection biases on results, respectively. Multivariate Cox proportional hazards regression was used to examine association between obtaining FUBC and 28-day all-cause mortality after adjustment for the propensity to obtain FUBC. FINDINGS: Among 766 patients with GN-BSI, 219 (28.6%) had FUBC obtained and 15 of 219 (6.8%) FUBC were persistently positive. Overall, median age was 67 years, 438 (57%) were women, 457 (60%) had urinary source of infection, and 426 (56%) had BSI due to Escherichia coli. Mortality was significantly lower in patients who had FUBC obtained than in those who did not have FUBC (6.3% vs. 11.7%, log-rank p = 0.03). Obtaining FUBC was independently associated with reduced mortality (hazards ratio 0.47, 95% confidence intervals: 0.23-0.87; p = 0.02) after adjustments for age, chronic comorbidities, acute severity of illness, appropriateness of empirical antimicrobial therapy, and propensity to obtain FUBC. INTERPRETATION: Improved survival in hospitalized patients with GN-BSI who had FUBC is consistent with the results of recent publications from Italy and North Carolina supporting utilization of FUBC in management of GN-BSI. FUNDING: This study had no funding source.

Application of Standardized Antimicrobial Administration Ratio as a Motivational Tool within a Multi-Hospital Healthcare System.

The standardized antimicrobial administration ratio (SAAR) is a novel antimicrobial stewardship metric that compares actual to expected antimicrobial use (AU). This prospective cohort study examines the utility of SAAR reporting and inter-facility comparisons as a motivational tool to improve overall and broad-spectrum AU within a three-hospital healthcare system. Transparent inter-facility comparisons were deployed during system-wide antimicrobial stewardship meetings beginning in October 2017. Stakeholders were advised to interpret the results to foster competition and incorporate SAAR data into focused antimicrobial stewardship interventions. Student's t-test was used to compare mean SAARs in the pre- (July 2017 through October 2017) and post-intervention periods (November 2017 through June 2019). The mean pre-intervention SAARs for hospitals A, B, and C were 0.69, 1.09, and 0.60, respectively. Hospital B experienced significant reductions in SAAR for overall AU (from 1.09 to 0.83; p < 0.001), broad-spectrum antimicrobials used for hospital-onset infections (from 1.36 to 0.81; p < 0.001), and agents used for resistant gram-positive infections in the intensive care units (from 1.27 to 0.72; p < 0.001) after the interventions. The alignment of the SAAR across the health-system and sustained reduction in overall and broad-spectrum AU through implementation of inter-facility comparisons demonstrate the utility in the motivational application of this antimicrobial use metric.

Risk and clinical outcomes of acute myocardial infarction and acute ischemic stroke following gram-negative bloodstream infection.

OBJECTIVES: This retrospective cohort study examines incidence, risk factors, and clinical outcomes of acute myocardial infarction (AMI) and acute ischemic stroke (AIS) within one year of gram-negative bloodstream infection (GN-BSI) based on predefined clinical criteria. METHODS: Hospitalized adults with GN-BSI at Prisma Health-Midlands hospitals in South Carolina, USA from 2010 through 2015 were identified. Kaplan-Meier analysis was used to determine incidence of AMI and AIS within one year after GN-BSI. Multivariate Cox proportional hazards regression models were used to examine risk factors for AMI or AIS and impact on 1-year mortality. RESULTS: Among 1292 patients with GN-BSI, 263 and 17 developed AMI and AIS within 1-year with incidences of 23.4% and 1.9%, respectively. Majority of AMI were type 2 (164; 62%); 99 patients had type 1 AMI with incidence of 8.9%. Age >65 years (hazard ratio [HR] 1.52, 95% CI: 1.17-1.99), prior coronary artery disease or stroke (HR 1.74, 95% CI: 1.34-2.25), hypertension (HR 1.55, 95% CI: 1.13-2.15), end-stage renal disease (HR 1.52, 95% CI: 1.09-2.08), and quick Pitt bacteremia score (HR 1.55 per point, 95% CI: 1.40-1.72) were predictors of AMI/AIS. Development of type 1 AMI or AIS after GN-BSI was independently associated with increased 1-year mortality (HR 1.47, 95% CI: 1.03-2.07). CONCLUSIONS: AMI and AIS occur frequently within one year of GN-BSI and have negative impact on 1-year survival. Future randomized clinical trials are needed to determine the most effective clinical interventions for prevention of AMI/AIS following BSI in high risk patients and improve survival after these events.

Novel method of calculating adjusted antibiotic use by microbiological burden.

OBJECTIVE: To determine the usefulness of adjusting antibiotic use (AU) by prevalence of bacterial isolates as an alternative method for risk adjustment beyond hospital characteristics. DESIGN: Retrospective, observational, cross-sectional study. SETTING: Hospitals in the southeastern United States. METHODS: AU in days of therapy per 1,000 patient days and microbiologic data from 2015 and 2016 were collected from 26 hospitals. The prevalences of Pseudomonas aeruginosa, extended-spectrum ß-lactamase (ESBL)-producing bacteria, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE) were calculated and compared to the average prevalence of all hospitals in the network. This proportion was used to calculate the adjusted AU (a-AU) for various categories of antimicrobials. For example, a-AU of antipseudomonal ß-lactams (APBL) was the AU of APBL divided by (prevalence of P. aeruginosa at that hospital divided by the average prevalence of P. aeruginosa). Hospitals were categorized by bed size and ranked by AU and a-AU, and the rankings were compared. RESULTS: Most hospitals in 2015 and 2016, respectively, moved ≥2 positions in the ranking using a-AU of APBL (15 of 24, 63%; 22 of 26, 85%), carbapenems (14 of 23, 61%; 22 of 25; 88%), anti-MRSA agents (13 of 23, 57%; 18 of 26, 69%), and anti-VRE agents (18 of 24, 75%; 15 of 26, 58%). Use of a-AU resulted in a shift in quartile of hospital ranking for 50% of APBL agents, 57% of carbapenems, 35% of anti-MRSA agents, and 75% of anti-VRE agents in 2015 and 50% of APBL agents, 28% of carbapenems, 50% of anti-MRSA agents, and 58% of anti-VRE agents in 2016. CONCLUSIONS: The a-AU considerably changes how hospitals compare among each other within a network. Adjusting AU by microbiological burden allows for a more balanced comparison among hospitals with variable baseline rates of resistant bacteria.