In-person prospective audit and feedback on an oncology ward: development of an immunocompromised antimicrobial stewardship program

Objective

To describe clinical syndromes, opportunities for antimicrobial optimization, and acceptance of recommendations made by an immunocompromised antimicrobial stewardship program performing in-person prospective audit and feedback (IPPAF) on inpatient oncology services.

Design

Retrospective cohort study.

Setting

Three inpatient oncology services including patients with solid tumor malignancies in an academic cancer center.

Patients

Hospitalized adults with oncologic malignancies receive antimicrobials for any indication.

Methods

We reviewed all patients receiving antimicrobials on inpatient oncology services who were included in IPPAF and prospectively documented clinical syndromes represented, most common recommendations, and acceptance rate. We also examined the standardized antimicrobial administration ratio (SAAR) for oncology units over the study period.

Results

Over 34 weeks, we performed 154 interventions for 138 patients. Metastatic malignancy was common (52%) and 90-day mortality was high (43%). Diagnostic uncertainty was common (33/154, 21%), as were cases of intra-abdominal pathology (30/154, 19%), pneumonia (25/154, 16%), and urinary tract infection (12/154, 8%). The most common recommendations were changes in duration (63/154, 41%) and stopping antimicrobials for syndromes determined to be noninfectious (29/154, 19%). Acceptance of interventions was high (77% overall) and several SAARs on the primary oncology unit significantly decreased after starting IPPAF.

Conclusions

We identified numerous opportunities for antimicrobial optimization among solid tumor malignancy patients. Most clinical syndromes were ones also encountered frequently in non-oncology populations, but several were unique and represented opportunities for targeted education.

Evaluating Antibiotic Misuse and Cost Analysis Among Hospitalized Dengue Virus-Infected Adults: Insights From a Retrospective Cohort Study

Background

Dengue is a prevalent cause of acute febrile illness, predominantly in Asia, where it necessitates supportive care without the need for antibiotics. This study aimed to evaluate antibiotic usage and analyze hospitalization costs among adults infected with the dengue virus.

Methods

This retrospective cohort study was conducted at the Hospital for Tropical Diseases, Thailand, in 2022. Two independent reviewers assessed all adult cases with confirmed dengue from 2016 to 2021. Determinants of inappropriateness were analyzed using Poisson regression.

Results

The study included 249 participants with over half presenting with severe dengue or dengue with warning signs upon admission. The cumulative incidence of antibiotic use was 9.3% (95% CI, 8.23-10.47), predominantly involving empirical treatment strategies. Ceftriaxone and doxycycline were the most frequently prescribed antibiotics. Notably, patients who received empirical antibiotics showed no definite or presumed bacterial infections. Among those who received definite strategies, inappropriate durations, including both short treatments and the overuse of broad-spectrum antibiotics, were observed. A private ward admission was identified as a significant predictor of inappropriate use, with an incidence rate ratio of 4.15 (95% CI, 1.16-14.82) compared with intensive care unit admission. Direct medical costs did not differ significantly between appropriate and inappropriate uses.

Conclusions

The incidence of antibiotic use among dengue cases was moderate; however, inappropriate use by indication was observed. Antimicrobial stewardship strategies should be encouraged, particularly in patients with dengue with warning signs admitted to a general or private ward. Direct medical costs between appropriate and inappropriate use were comparable.

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Prospective Audit and Feedback for Antimicrobial Treatment of Patients Receiving Renal Replacement Therapy in Community-Based University Hospitals: A before-and-after Study

In South Korea, because of manpower and budgetary limitations, antimicrobial stewardship programs have relied on preauthorization. This study analyzed the impact of a prospective audit and feedback (PAF) program targeting inpatients undergoing intermittent hemodialysis or continuous renal replacement therapy, which was implemented at two community-based university hospitals. During three years of PAF, 27,906 antimicrobial prescriptions were reviewed, with 622 (2.2%) interventions. The mean incidence density per 1000 patient days of multidrug-resistant organisms, except for carbapenem-resistant Acinetobacter baumannii, decreased in the study population, whereas it increased among inpatients. Multivariable Poisson regression analysis revealed that after PAF, the incidences of vancomycin-resistant Enterococcus and mortality decreased (incidence risk ratio, 95% confidence interval: 0.53, 0.31-0.93 and 0.70, 0.55-0.90, respectively). Notably, after PAF, incorrect antimicrobial dosing rates significantly decreased (tau -0.244; p = 0.02). However, the incidences of other multidrug-resistant organisms, Clostridioides difficile, length of stay, and readmission did not significantly change. This study shows that in patients undergoing intermittent hemodialysis or continuous renal replacement, targeted PAF can significantly reduce multidrug-resistant organism rates and all-cause hospital mortality, despite limited resources. Furthermore, it can improve antimicrobial dosage accuracy.

Appropriateness of antibiotic prescribing varies by clinical services at United States children's hospitals

OBJECTIVE

To describe patterns of inappropriate antibiotic prescribing at US children's hospitals and how these patterns vary by clinical service.

DESIGN

Serial, cross-sectional study using quarterly surveys.

SETTING

Surveys were completed in quarter 1 2019-quarter 3 2020 across 28 children's hospitals in the United States.

PARTICIPANTS

Patients at children's hospitals with ≥1 antibiotic order at 8:00 a.m. on institution-selected quarterly survey days.

METHODS

Antimicrobial stewardship physicians and pharmacists collected data on antibiotic orders and evaluated appropriateness of prescribing. The primary outcome was percentage of inappropriate antibiotics, stratified by clinical service and antibiotic class. Secondary outcomes included reasons for inappropriate use and association of infectious diseases (ID) consultation with appropriateness.

RESULTS

Of 13,344 orders, 1,847 (13.8%) were inappropriate; 17.5% of patients receiving antibiotics had ≥1 inappropriate order. Pediatric intensive care units (PICU) and hospitalists contributed the most inappropriate orders (n = 384 and n = 314, respectively). Surgical subspecialists had the highest percentage of inappropriate orders (22.5%), and 56.8% of these were for prolonged or unnecessary surgical prophylaxis. ID consultation in the previous 7 days was associated with fewer inappropriate orders (15% vs 10%; P < .001); this association was most pronounced for hospitalist, PICU, and surgical and medical subspecialty services.

CONCLUSIONS

Inappropriate antibiotic use for hospitalized children persists and varies by clinical service. Across 28 children's hospitals, PICUs and hospitalists contributed the most inappropriate antibiotic orders, and surgical subspecialists' orders were most often judged inappropriate. Understanding service-specific prescribing patterns will enable antimicrobial stewardship programs to better design interventions to optimize antibiotic use.

Antimicrobial Stewardship in the Hospital Setting: A Narrative Review

The increasing global threat of antibiotic resistance, which has resulted in countless fatalities due to untreatable infections, underscores the urgent need for a strategic action plan. The acknowledgment that humanity is perilously approaching the "End of the Miracle Drugs" due to the unjustifiable overuse and misuse of antibiotics has prompted a critical reassessment of their usage. In response, numerous relevant medical societies have initiated a concerted effort to combat resistance by implementing antibiotic stewardship programs within healthcare institutions, grounded in evidence-based guidelines and designed to guide antibiotic utilization. Crucial to this initiative is the establishment of multidisciplinary teams within each hospital, led by a dedicated Infectious Diseases physician. This team includes clinical pharmacists, clinical microbiologists, hospital epidemiologists, infection control experts, and specialized nurses who receive intensive training in the field. These teams have evidence-supported strategies aiming to mitigate resistance, such as conducting prospective audits and providing feedback, including the innovative 'Handshake Stewardship' approach, implementing formulary restrictions and preauthorization protocols, disseminating educational materials, promoting antibiotic de-escalation practices, employing rapid diagnostic techniques, and enhancing infection prevention and control measures. While initial outcomes have demonstrated success in reducing resistance rates, ongoing research is imperative to explore novel stewardship interventions.

Impact of prolonged carbapenem use-focused antimicrobial stewardship on antimicrobial consumption and factors affecting acceptance of recommendations: a quasi-experimental study

This study aimed to assess the impact of a prolonged carbapenem use-focused antimicrobial stewardship program (ASP) on antimicrobial consumption and clinical outcomes and to analyze factors affecting adherence to interventions. Patients prescribed carbapenems for ≥ 2 weeks received intervention. Interrupted time-series analysis was performed to compare antimicrobial consumption before and after intervention. Factors associated with non-adherence to intervention were investigated. Of 273 patients who were eligible for intervention, discontinuation or de-escalation was recommended in 256 (94.1%) and intervention was accepted in 136 (53.1%) patients. Before intervention, carbapenem consumption significantly increased to 1.14 days of therapy (DOT)/1000 patient days (PD)/month (P = 0.018). However, it significantly declined by - 2.01 DOT/1000 PD/month without an increase in other antibiotic consumption (P < 0.001). Factors affecting non-adherence to intervention were younger age (odds ratio [OR] = 0.98; 95% confidence interval [CI] 0.96-1.00), solid organ malignancy (OR = 2.53, 95% CI 1.16-5.50), and pneumonia (OR = 2.59, 95% CI 1.08-6.17). However, ASP intervention was not associated with clinical outcomes such as length of hospital stay or mortality. Prolonged carbapenem prescription-focused ASP significantly reduced carbapenem consumption without adverse outcomes. Non-adherence to interventions was attributed more to prescriber-related factors, such as attitude, than patient-related factors including clinical severity.

Evaluation of the initial timing of infection control pharmacist-driven audit and monitoring of vancomycin therapy in patients with infectious diseases: A retrospective observational study

BACKGROUND

Early monitoring and feedback on the treatment of infectious diseases are some of the methods for optimising antimicrobial treatment throughout the treatment period. Prospective audits and feedback interventions have also been shown to improve antimicrobial use and reduce antimicrobial resistance. We examined the appropriate use of antimicrobials by focusing on the initial timing for audits and feedback intervention of antimicrobial prescription by Infection Control Team pharmacists.

METHODS

We conducted a retrospective observational study in a university hospital in Tokyo, Japan from 1 January 2019 to 31 May 2021. We retrospectively enrolled patients with infections and those patients suspected of having an infection, who were administered vancomycin and assessed at our hospital. The definition of primary outcome was the maintenance of target vancomycin trough blood concentrations of 10-20 μg/ml during treatment. Multivariable logistic regression and multivariate linear regression analyses were performed to test the effectiveness of the initial timing of the intervention by Infection Control Team pharmacists as the explanatory variable.

RESULTS

A total of 638 patients were included in this study, with a median age of 69 years (interquartile range: 54-78 years). Multivariable logistic regression revealed that the maintenance of target vancomycin trough concentrations was not associated with the timing of the audit and the initiation of monitoring by Infection Control Team pharmacists (adjusted odds ratio: 0.99, 95% confidence interval: 0.99-1.00, p = 0.990). Multivariate linear regression revealed that the duration of vancomycin administration was significantly correlated with the timing of initiation of monitoring by Infection Control Team pharmacists (adjusted estimate: 0.0227, standard error: 0.0051, p = 0.012).

CONCLUSIONS

Our study showed that early initiation of a comprehensive audit and monitoring by Infection Control Team pharmacists did not affect the maintenance of the target vancomycin trough blood concentration. However, it reduced the duration of vancomycin administration.

Establishing an effective antimicrobial stewardship program at four secondary-care hospitals in India using a hub-and-spoke model

Background

The high burden of antimicrobial resistance in India necessitates the urgent implementation of antimicrobial stewardship programs (ASPs) in all healthcare settings in India. Most ASPs are based at tertiary-care centers, with sparse data available regarding the effectiveness of an ASP in a low-resource primary/secondary-care setting.

Methods

We adopted a hub-and-spoke model to implement ASPs in 4 low-resource, secondary-care healthcare settings. The study included 3 phases measuring antimicrobial consumption data. In the baseline phase, we measured days on antimicrobial therapy (DOTs) with no feedback provided. This was followed by the implementation of a customized intervention package. In the postintervention phase, prospective review and feedback were offered by a trained physician or ASP pharmacist, and days of therapy (DOT) were measured.

Results

In the baseline phase, 1,459 patients from all 4 sites were enrolled; 1,233 patients were enrolled in the postintervention phase. Both groups had comparable baseline characteristics. The key outcome, DOT per 1,000 patient days, was 1,952.63 in the baseline phase and significantly lower in the post-intervention period, at 1,483.06 (P = .001). Usage of quinolone, macrolide, cephalosporin, clindamycin, and nitroimidazole significantly decreased in the postintervention phase. Also, the rate of antibiotic de-escalation was significantly higher in the postintervention phase than the baseline phase (44% vs 12.5%; P < .0001), which suggests a definite trend toward judicious use of antibiotics. In the postintervention phase, 79.9% of antibiotic use was justified. Overall, the recommendations given by the ASP team were fully followed in 946 cases (77.7%), partially followed in 59 cases (4.8%), and not followed in 137 cases (35.7%). No adverse events were noted.

Conclusion

Our hub-and-spoke model of ASP was successful in implementing ASPs in secondary-care hospitals in India, which are urgently needed.

Evaluation of an Opt-Out Protocol for Antibiotic De-Escalation in Patients With Suspected Sepsis: A Multicenter, Randomized, Controlled Trial

BACKGROUND

Sepsis guidelines recommend daily review to de-escalate or stop antibiotics in appropriate patients. This randomized, controlled trial evaluated an opt-out protocol to decrease unnecessary antibiotics in patients with suspected sepsis.

METHODS

We evaluated non-intensive care adults on broad-spectrum antibiotics despite negative blood cultures at 10 US hospitals from September 2018 through May 2020. A 23-item safety check excluded patients with ongoing signs of systemic infection, concerning or inadequate microbiologic data, or high-risk conditions. Eligible patients were randomized to the opt-out protocol vs usual care. Primary outcome was post-enrollment antibacterial days of therapy (DOT). Clinicians caring for intervention patients were contacted to encourage antibiotic discontinuation using opt-out language. If continued, clinicians discussed the rationale for continuing antibiotics and de-escalation plans. To evaluate those with zero post-enrollment DOT, hurdle models provided 2 measures: odds ratio of antibiotic continuation and ratio of mean DOT among those who continued antibiotics.

RESULTS

Among 9606 patients screened, 767 (8%) were enrolled. Intervention patients had 32% lower odds of antibiotic continuation (79% vs 84%; odds ratio, 0.68; 95% confidence interval [CI], .47-.98). DOT among those who continued antibiotics were similar (ratio of means, 1.06; 95% CI, .88-1.26). Fewer intervention patients were exposed to extended-spectrum antibiotics (36% vs 44%). Common reasons for continuing antibiotics were treatment of localized infection (76%) and belief that stopping antibiotics was unsafe (31%). Thirty-day safety events were similar.

CONCLUSIONS

An antibiotic opt-out protocol that targeted patients with suspected sepsis resulted in more antibiotic discontinuations, similar DOT when antibiotics were continued, and no evidence of harm.

CLINICAL TRIALS REGISTRATION

NCT03517007.

Antibiotic review kit for hospitals (ARK-Hospital): a stepped-wedge cluster-randomised controlled trial

BACKGROUND

Strategies to reduce antibiotic overuse in hospitals depend on prescribers taking decisions to stop unnecessary antibiotic use. There is scarce evidence for how to support these decisions. We evaluated a multifaceted behaviour change intervention (ie, the antibiotic review kit) designed to reduce antibiotic use among adult acute general medical inpatients by increasing appropriate decisions to stop antibiotics at clinical review.

METHODS

We performed a stepped-wedge, cluster (hospital)-randomised controlled trial using computer-generated sequence randomisation of eligible hospitals in seven calendar-time blocks in the UK. Hospitals were eligible for inclusion if they admitted adult non-elective general or medical inpatients, had a local representative to champion the intervention, and could provide the required study data. Hospital clusters were randomised to an implementation date occurring at 1-2 week intervals, and the date was concealed until 12 weeks before implementation, when local preparations were designed to start. The intervention effect was assessed using data from pseudonymised routine electronic health records, ward-level antibiotic dispensing, Clostridioides difficile tests, prescription audits, and an implementation process evaluation. Co-primary outcomes were monthly antibiotic defined daily doses per adult acute general medical admission (hospital-level, superiority) and all-cause mortality within 30 days of admission (patient level, non-inferiority margin of 5%). Outcomes were assessed in the modified intention-to-treat population (ie, excluding sites that withdrew before implementation). Intervention effects were assessed by use of interrupted time series analyses within each site, estimating overall effects through random-effects meta-analysis, with heterogeneity across prespecified potential modifiers assessed by use of meta-regression. This trial is completed and is registered with ISRCTN, ISRCTN12674243.

FINDINGS

58 hospital organisations expressed an interest in participating. Three pilot sites implemented the intervention between Sept 25 and Nov 20, 2017. 43 further sites were randomised to implement the intervention between Feb 12, 2018, and July 1, 2019, and seven sites withdrew before implementation. 39 sites were followed up for at least 14 months. Adjusted estimates showed reductions in total antibiotic defined daily doses per acute general medical admission (-4·8% per year, 95% CI -9·1 to -0·2) following the intervention. Among 7 160 421 acute general medical admissions, the ARK intervention was associated with an immediate change of -2·7% (95% CI -5·7 to 0·3) and sustained change of 3·0% (-0·1 to 6·2) in adjusted 30-day mortality.

INTERPRETATION

The antibiotic review kit intervention resulted in sustained reductions in antibiotic use among adult acute general medical inpatients. The weak, inconsistent intervention effects on mortality are probably explained by the onset of the COVID-19 pandemic. Hospitals should use the antibiotic review kit to reduce antibiotic overuse.

FUNDING

UK National Institute for Health and Care Research.

Nurses' and Physicians' Responses to a New Active Antimicrobial Stewardship Program: A Two-Phase Study of Responses and Their Underlying Perceptions and Values

BACKGROUND

Successful implementation of an antimicrobial stewardship program (ASP) depends on staff members' response to it. We introduced at the Hadassah Medical Center in Israel a significant change to our long-standing handshake ASP. As before, the new ASP involved a dialogue between the treating physician and the infectious disease physician over the appropriate antibiotic therapy. The main change was that the infectious disease physician's decision was now integrated into the patient's electronic medical record (EMR). Our purpose in this study was to uncover the concerns and expectations of physicians and nurses towards the new ASP, before and after its implementation, and link these with their basic perceptions of the ASP and their personal values.

METHODS

We used open-ended questions and Likert-type scales to study staff members' personal values, basic perceptions of the new system, and attitudes towards it, both before (N = 143), and one year after (N = 103) the system's implementation. Relationships of the system's perceptions and personal values with attitudes toward the system were tested using correlations and multiple regression analyses.

RESULTS

Prior to its implementation, physicians and nurses had multiple concerns about the new ASP's demandingness and inefficiency and its threat to physicians' autonomy and expertise. They also had positive expectations for benefits to the hospital, the patients and society. A year later, following the system's implementation, concerns dissipated, whereas the perceived benefits remained. Moreover, staff members' attitudes tended to be more positive among those who value conformity.

CONCLUSION

Introducing new ASPs is a challenging process. Our findings suggest that hospital staff's initial concerns about the new ASP were primarily about its ease of use and demandingness. These concerns, which diminished over time, were linked with perceived satisfaction with the system. Conformity values had an indirect effect in predicting satisfaction with the system, mediated by perceptions of the system as straightforward.

Point-prevalence survey of antibiotic use at three public referral hospitals in Kenya

Antimicrobial stewardship encourages appropriate antibiotic use, the specific activities of which will vary by institutional context. We investigated regional variation in antibiotic use by surveying three regional public hospitals in Kenya. Hospital-level data for antimicrobial stewardship activities, infection prevention and control, and laboratory diagnostic capacities were collected from hospital administrators, heads of infection prevention and control units, and laboratory directors, respectively. Patient-level antibiotic use data were abstracted from medical records using a modified World Health Organization point-prevalence survey form. Altogether, 1,071 consenting patients were surveyed at Kenyatta National Hospital (KNH, n = 579), Coast Provincial General Hospital (CPGH, n = 229) and Moi Teaching and Referral Hospital (MTRH, n = 263). The majority (67%, 722/1071) were ≥18 years and 53% (563/1071) were female. Forty-six percent (46%, 489/1071) were receiving at least one antibiotic. Antibiotic use was higher among children <5 years (70%, 150/224) than among other age groups (40%, 339/847; P < 0.001). Critical care (82%, 14/17 patients) and pediatric wards (59%, 155/265) had the highest proportion of antibiotic users. Amoxicillin/clavulanate was the most frequently used antibiotic at KNH (17%, 64/383 antibiotic doses), and ceftriaxone was most used at CPGH (29%, 55/189) and MTRH (31%, 57/184). Forty-three percent (326/756) of all antibiotic prescriptions had at least one missed dose recorded. Forty-six percent (204/489) of patients on antibiotics had a specific infectious disease diagnosis, of which 18% (37/204) had soft-tissue infections, 17% (35/204) had clinical sepsis, 15% (31/204) had pneumonia, 13% (27/204) had central nervous system infections and 10% (20/204) had obstetric or gynecological infections. Of these, 27% (56/204) had bacterial culture tests ordered, with culture results available for 68% (38/56) of tests. Missed antibiotic doses, low use of specimen cultures to guide therapy, high rates of antibiotic use, particularly in the pediatric and surgical population, and preference for broad-spectrum antibiotics suggest antibiotic use in these tertiary care hospitals is not optimal. Antimicrobial stewardship programs, policies, and guidelines should be tailored to address these areas.

Impact of an electronic alert on prescription patterns of meropenem, voriconazole and caspofungin

BACKGROUND

Antimicrobial stewardship programs promote the appropriate use of antimicrobial substances through the implementation of evidence-based, active and passive interventions. We analyzed the effect of a computer-assisted intervention on antimicrobial use in a tertiary care hospital.

METHODS

Between 2011 and 2016 we introduced an electronic alert for patients being prescribed meropenem, voriconazole and caspofungin. At prescription and at day 3 of treatment, physicians were informed about the risk related to these antimicrobial substances by an electronic alert in the medical records. Physicians were invited to revoke or confirm the prescription and to contact the infectious disease (ID) team. Using interrupted time series regression, the days of therapy (DOTs) and the number of prescriptions before and after the intervention were compared.

RESULTS

We counted 64,281 DOTs for 5549 prescriptions during 4100 hospital stays. Overall, the DOTs decreased continuously over time. An additional benefit of the alert could not be observed. Similarly, the number of prescriptions decreased over time, without significant effect of the intervention. When considering the three drugs separately, the alert impacted the duration (change in slope of DOTs/1000 bed days; P = 0.0017) as well as the number of prescriptions (change in slope of prescriptions/1000 bed days; P < 0.001) of voriconazole only.

CONCLUSIONS

The introduction of the alert lowered prescriptions of voriconazole only. Thus, self-stewardship alone seems to have a limited impact on electronic prescriptions of anti-infective substances. Additional measures such as face-to-face prompting with ID physicians or audit and feedback are indispensable to optimize antimicrobial use.

Acceptability and effectiveness of antimicrobial stewardship implementation strategies on fluoroquinolone prescribing

OBJECTIVE

To assess the effectiveness and acceptability of antimicrobial stewardship-focused implementation strategies on inpatient fluoroquinolones.

METHODS

Stewardship champions at 15 hospitals were surveyed regarding the use and acceptability of strategies to improve fluoroquinolone prescribing. Antibiotic days of therapy (DOT) per 1,000 days present (DP) for sites with and without prospective audit and feedback (PAF) and/or prior approval were compared.

RESULTS

Among all of the sites, 60% had PAF or prior approval implemented for fluoroquinolones. Compared to sites using neither strategy (64.2 ± 34.4 DOT/DP), fluoroquinolone prescribing rates were lower for sites that employed PAF and/or prior approval (35.5 ± 9.8; P = .03) and decreased from 2017 to 2018 (P < .001). This decrease occurred without an increase in advanced-generation cephalosporins. Total antibiotic rates were 13% lower for sites with PAF and/or prior approval, but this difference did not reach statistical significance (P = .20). Sites reporting that PAF and/or prior approval were "completely" accepted had lower fluoroquinolone rates than sites where it was "moderately" accepted (34.2 ± 5.7 vs 48.7 ± 4.5; P < .01). Sites reported that clinical pathways and/or local guidelines (93%), prior approval (93%), and order forms (80%) "would" or "may" be effective in improving fluoroquinolone use. Although most sites (73%) indicated that requiring infectious disease consults would or may be effective in improving fluoroquinolones, 87% perceived implementation to be difficult.

CONCLUSIONS

PAF and prior approval implementation strategies focused on fluoroquinolones were associated with significantly lower fluoroquinolone prescribing rates and nonsignificant decreases in total antibiotic use, suggesting limited evidence for class substitution. The association of acceptability of strategies with lower rates highlights the importance of culture. These results may indicate increased acceptability of implementation strategies and/or sensitivity to FDA warnings.

Outpatient Antibiotic Prescribing Patterns and Appropriateness for Children in Primary Healthcare Settings in Beijing City, China, 2017-2019

(1) Background: Few studies have focused on antibiotic use and appropriateness in children in primary health institutions (PHIs). This study aimed to identify the patterns and appropriateness of antibiotic use for children in PHIs in Beijing, China. (2) Methods: Outpatient prescriptions of 327 PHIs from 2017 to 2019 for patients <18 years old were collected. Prescriptions were described using quantity indicators. Antibiotics were categorized according to ATC classification J01 and Access, Watch, Reserve grouping. Appropriateness was reviewed by experts using three subtypes of irrational prescriptions (irregular, inappropriate, and abnormal). (3) Results: 20,618 prescriptions were collected in total. The antibiotic prescription rate (APR) was 15.1% (N = 3113). Among antibiotic prescriptions, J01FA Macrolides were the most used (N = 1068, 34.9%). The Watch group constituted 89.0% (N = 2818) of total antibiotic use. Bronchitis (N = 1059, 35.2%) was the most common diagnosis. A total of 292 instances of irrational antibiotic use were identified, with inappropriate prescriptions being the most prevalent subtype (N = 233, 79.8%). (4) Conclusion: Although APR for children in PHIs in Beijing was relatively low, the pattern of antibiotic use differed from other countries. Further studies are needed to optimize antibiotic use for children in PHIs under different levels of economic development.

Effect of discontinuation of an antimicrobial stewardship programme on the antibiotic usage pattern

OBJECTIVES

This study aimed to analyse the effect of discontinuation of antimicrobial stewardship programme (ASP) activity on the usage pattern of antibiotics.

METHODS

An interrupted time-series analysis assessing the trends in antibiotic use was conducted between September 2015 and August 2019 in an 859-bed university-affiliated hospital in Korea, where all ASP activities were discontinued in March 2018. The major activity of the ASP was a restrictive antibiotic programme.

RESULTS

The use of restrictive antibiotics increased immediately after the discontinuation of the ASP by 41.06 days of therapy (DOT)/1000 patient-days in the general ward (95% confidence interval (CI) 21.04-61.08) and by 391.04 DOT/1000 patient-days in the intensive care unit (ICU) (95%CI 207.56-574.51). In addition, there were positive changes in the slope for the use of restrictive antibiotics in the general ward (7.06 DOT/1000 patient-days per month, 95%CI 4.63-9.50) and ICU (35.95 DOT/1000 patient-days per month, 95%CI 18.70-53.19). The use of broad-spectrum antibiotics in the general ward significantly decreased (-87.54 DOT/1000 patient-days, 95%CI -149.29 to -25.79). For non-broad-spectrum antibiotics, there were positive changes in the slope in the general ward (16.54 DOT/1000 patient-days per month, 95%CI 12.99-20.09) and ICU (12.85 DOT/1000 patient-days per month, 95%CI 2.32-23.38).

CONCLUSIONS

After discontinuation of the ASP, antibiotic usage patterns rapidly returned to the patterns prior to the implementation of the programme.

Decreasing ICU-associated Clostridioides difficile infection through fluoroquinolone restriction, the FIRST trial: a study protocol

INTRODUCTION

Clostridioides difficile infection (CDI) is one of the most common healthcare-associated infections in the USA, having high incidence in intensive care units (ICU). Antibiotic use increases risk of CDI, with fluoroquinolones (FQs) particularly implicated. In healthcare settings, antibiotic stewardship (AS) and infection control interventions are effective in CDI control, but there is little evidence regarding the most effective AS interventions. Preprescription authorisation (PPA) restricting FQs is a potentially promising AS intervention to reduce CDI. The FQ Restriction for the Prevention of CDI (FIRST) trial will evaluate the effectiveness of an FQ PPA intervention in reducing CDI rates in adult ICUs compared with preintervention care, and evaluate implementation effectiveness using a human-factors and systems engineering model.

METHODS AND ANALYSIS

This is a multisite, stepped-wedge, cluster, effectiveness-implementation clinical trial. The trial will take place in 12 adult medical-surgical ICUs with ≥10 beds, using Epic as electronic health record (EHR) and pre-existing AS programmes. Sites will receive facilitated implementation support over the 15-month trial period, succeeded by 9 months of follow-up. The intervention comprises a clinical decision support system for FQ PPA, integrated into the site EHRs. Each ICU will be considered a single site and all ICU admissions included in the analysis. Clinical data will be extracted from EHRs throughout the trial and compared with the corresponding pretrial period, which will constitute the baseline for statistical analysis. Outcomes will include ICU-onset CDI rates, FQ days of therapy (DOT), alternative antibiotic DOT, average length of stay and hospital mortality. The study team will also collect implementation data to assess implementation effectiveness using the Systems Engineering Initiative for Patient Safety model.

ETHICS AND DISSEMINATION

The trial was approved by the Institutional Review Board at the University of Wisconsin-Madison (2018-0852-CP015). Results will be made available to participating sites, funders, infectious disease societies, critical care societies and other researchers.

TRIAL REGISTRATION NUMBER

NCT03848689.

Opportunities to Improve Antibiotic Appropriateness in U.S. ICUs: A Multicenter Evaluation

OBJECTIVES

To use a standardized tool for a multicenter assessment of antibiotic appropriateness in ICUs and identify local antibiotic stewardship improvement opportunities.

DESIGN

Pilot point prevalence conducted on October 5, 2016; point prevalence survey conducted on March 1, 2017.

SETTING

ICUs in 12 U.S. acute care hospitals with median bed size 563.

PATIENTS

Receiving antibiotics on participating units on March 1, 2017.

INTERVENTIONS

The Centers for Disease Control and Prevention tool for the Assessment of Appropriateness of Inpatient Antibiotics was made actionable by an expert antibiotic stewardship panel and implemented across hospitals. Data were collected by antibiotic stewardship program personnel at each hospital, deidentified and submitted in aggregate for benchmarking. hospital personnel identified most salient reasons for inappropriate use by category and agent.

MEASUREMENTS AND MAIN RESULTS

Forty-seven ICUs participated. Most hospitals (83%) identified as teaching with median licensed ICU beds of 70. On March 1, 2017, 362 (54%) of 667 ICU patients were on antibiotics (range, 8-81 patients); of these, 112 (31%) were identified as inappropriate and administered greater than 72 hours among all 12 hospitals (range, 9-82%). Prophylactic antibiotic regimens and PICU patients demonstrated a statistically significant risk ratio of 1.76 and 1.90 for inappropriate treatment, respectively. Reasons for inappropriate use included unnecessarily broad spectrum (29%), no infection or nonbacterial syndrome (22%), and duration longer than necessary (21%). Of patients on inappropriate antibiotic therapy in surgical ICUs, a statistically significant risk ratio of 2.59 was calculated for noninfectious or nonbacterial reasons for inappropriate therapy.

CONCLUSIONS

In this multicenter point prevalence study, 31% of ICU antibiotic regimens were inappropriate; prophylactic regimens were often inappropriate across different ICU types, particularly in surgical ICUs. Engaging intensivists in antibiotic stewardship program efforts is crucial to sustain the efficacy of antibiotics and quality of infectious diseases care in critical care settings. This study underscores the value of standardized assessment tools and benchmarking to be shared with local leaders for targeted antibiotic stewardship program interventions.

Using Audit and Feedback to Improve Antimicrobial Prescribing in Emergency Departments: A Multicenter Quasi-Experimental Study in the Veterans Health Administration

Background

In this pilot trial, we evaluated whether audit-and-feedback was a feasible strategy to improve antimicrobial prescribing in emergency departments (EDs).

Methods

We evaluated an audit-and-feedback intervention using a quasi-experimental interrupted time-series design at 2 intervention and 2 matched-control EDs; there was a 12-month baseline, 1-month implementation, and 11-month intervention period. At intervention sites, clinicians received (1) a single, one-on-one education about antimicrobial prescribing for common infections and (2) individualized feedback on total and condition-specific (uncomplicated acute respiratory infection [ARI]) antimicrobial use with peer-to-peer comparisons at baseline and every quarter. The primary outcome was the total antimicrobial-prescribing rate for all visits and was assessed using generalized linear models. In an exploratory analysis, we measured antimicrobial use for uncomplicated ARI visits and manually reviewed charts to assess guideline-concordant management for 6 common infections.

Results

In the baseline and intervention periods, intervention sites had 28 016 and 23 164 visits compared to 33 077 and 28 835 at control sites. We enrolled 27 of 31 (87.1%) eligible clinicians; they acknowledged receipt of 33.3% of feedback e-mails. Intervention sites compared with control sites had no absolute reduction in their total antimicrobial rate (incidence rate ratio = 0.99; 95% confidence interval, 0.98-1.01). At intervention sites, antimicrobial use for uncomplicated ARIs decreased (68.6% to 42.4%; P < .01) and guideline-concordant management improved (52.1% to 72.5%; P < .01); these improvements were not seen at control sites.

Conclusions

At intervention sites, total antimicrobial use did not decrease, but an exploratory analysis showed reduced antimicrobial prescribing for viral ARIs. Future studies should identify additional targets for condition-specific feedback while exploring ways to make electronic feedback more acceptable.

Sustainability of Handshake Stewardship: Extending a Hand Is Effective Years Later

BACKGROUND

Children's Hospital Colorado created a unique method of antimicrobial stewardship, called handshake stewardship, that effectively decreased hospital anti-infective use and costs in its pilot year (2013). Handshake stewardship is distinguished by: (1) the lack of prior authorization; (2) a review of all prescribed anti-infectives; (3) a shared review by the physician and the pharmacist; and (4) a daily, rounding-based, in-person approach to supporting providers. We sought to reevaluate the outcomes of the program after 5 years of experience, totaling 8 years of data.

METHODS

We retrospectively measured anti-infective (antibiotic, antiviral, antifungal) use hospital-wide by unit and by drug for an 8-year period spanning October 2010 to October 2018. Aggregated monthly use was measured in days of therapy per thousand patient days (DOT/1000 PD). The percentage of children admitted ever receiving an anti-infective was also measured, as well as severity-adjusted mortality, readmissions, and lengths of stay.

RESULTS

Hospital-wide mean anti-infective use significantly decreased, from 891 (95% confidence interval [CI] 859-923) in the pre-implementation phase to 655 (95% CI 637-694) DOT/1000 PD in post-implementation Year 5; in a segmented regression time series analysis, this was a rate of -2.6 DOT/1000 PD (95% CI -4.8 to -0.4). This is largely attributable to decreased antibacterial use, from 704 (95% CI 686-722) to 544 (95% CI 525 -562) DOT/1000 PD. The percentage of children ever receiving an anti-infective during admission likewise declined, from 65% to 52% (95% CI 49-54). There were no detrimental effects on severity adjusted mortality, readmissions, or lengths of stay.

CONCLUSIONS

The handshake method is an effective and sustainable approach to stewardship.

A modified Delphi approach to develop a trial protocol for antibiotic de-escalation in patients with suspected sepsis

Background:

Early administration of antibiotics in sepsis is associated with improved patient outcomes, but safe and generalizable approaches to de-escalate or discontinue antibiotics after suspected sepsis events are unknown.

Methods:

We used a modified Delphi approach to identify safety criteria for an opt-out protocol to guide de-escalation or discontinuation of antibiotic therapy after 72 hours in non-ICU patients with suspected sepsis. An expert panel with expertise in antimicrobial stewardship and hospital epidemiology rated 48 unique criteria across 3 electronic survey rating tools. Criteria were rated primarily based on their impact on patient safety and feasibility for extraction from electronic health record review. The 48 unique criteria were rated by anonymous electronic survey tools, and the results were fed back to the expert panel participants. Consensus was achieved to either retain or remove each criterion.

Results:

After 3 rounds, 22 unique criteria remained as part of the opt-out safety checklist. These criteria included high-risk comorbidities, signs of severe illness, lack of cultures during sepsis work-up or antibiotic use prior to blood cultures, or ongoing signs and symptoms of infection.

Conclusions:

The modified Delphi approach is a useful method to achieve expert-level consensus in the absence of evidence suifficient to provide validated guidance. The Delphi approach allowed for flexibility in development of an opt-out trial protocol for sepsis antibiotic de-escalation. The utility of this protocol should be evaluated in a randomized controlled trial.

Effectiveness and Acceptance of Multimodal Antibiotic Stewardship Program: Considering Progressive Implementation and Complementary Strategies

Multiple modes of interventions are available when implementing an antibiotic stewardship program (ASP), however, their complementarity has not yet been assessed. In a 938-bed hospital, we sequentially implemented four combined modes of interventions over one year, centralized by one infectious diseases specialist (IDS): (1) on-request infectious diseases specialist consulting service (IDSCS), (2) participation in intensive care unit meetings, (3) IDS intervention triggered by microbiological laboratory meetings, and (4) IDS intervention triggered by pharmacist alert. We assessed the complementarity of the different cumulative actions through quantitative and qualitative analysis of all interventions traced in the electronic medical record. We observed a quantitative and qualitative complementarity between interventions directly correlating to a decrease in antibiotic use. Quantitatively, the number of interventions has doubled after implementation of IDS intervention triggered by pharmacist alert. Qualitatively, these kinds of interventions led mainly to de-escalation or stopping of antibiotic therapy (63%) as opposed to on-request IDSCS (32%). An overall decrease of 14.6% in antibiotic use was observed (p = 0.03). Progressive implementation of the different interventions showed a concrete complementarity of these actions. Combined actions in ASPs could lead to a significant decrease in antibiotic use, especially regarding critical antibiotic prescriptions, while being well accepted by prescribers.

Barriers to Adherence to Antimicrobial Stewardship Postprescription Review and Feedback For Broad-Spectrum Antimicrobial Agents: A Nested Case-Control Study

Background

Postprescription review and feedback (PPRF) is one of the most common strategies in antimicrobial stewardship program (ASP) intervention. However, disagreements between the prescribers and ASP personnel can occur. The aim of the present study was to identify the factors associated with nonadherence to PPRF intervention.

Methods

The present retrospective nested case-control study was performed at a tertiary care center, which has been conducting a once-weekly PPRF for carbapenems and piperacillin/tazobactam since 2014. Nonadherence to ASP recommendations was defined as the failure of the primary care team to modify or stop antimicrobial therapy 72 hours after the issuance of PPRF recommendations. Factors associated with nonadherence to PPRF intervention were identified using multivariate logistic regression analysis.

Results

In total, 2466 instances of PPRF in 1714 cases between April 2014 and September 2019 were found. The nonadherence rate was 5.9%, and 44 cases were found in which carbapenems or piperacillin/tazobactam continued to be used against PPRF recommendations. Factors associated with nonadherence to PPRF recommendations were a previous history of hospitalization within 90 days (adjusted odds ratio [aOR], 2.62; 95% confidence interval [CI], 1.18-5.81) and a rapidly fatal McCabe score at the time of PPRF intervention (aOR, 2.87; 95% CI, 1.18-6.98). A review of the narrative comments in the electronic medical records indicated that common reasons for nonadherence were "the patient was sick" (n = 12; 27.3%) and "the antimicrobial seemed to be clinically effective" (n = 9; 20.5%).

Conclusions

Nonadherence to PPRF recommendations was relatively uncommon at the study institution. However, patients with a severe disease condition frequently continued to receive broad-spectrum antimicrobials against PPRF recommendations. Understanding physicians' cognitive process in nonadherence to ASP recommendations and ASP interventions targeting medical subspecialties caring for severely ill patients is needed to improve ASP.

Impact of a Prescriber-driven Antibiotic Time-out on Antibiotic Use in Hospitalized Patients

A multicenter quasi-experimental study of a provider-driven antibiotic "time-out" in 3470 antibiotic courses showed no difference in antibiotic use before and after implementation, but did show a decrease in inappropriate therapy (45% vs 31%, P < .05). Single time-outs without input from antibiotic stewardship teams are insufficient to optimize prescribing.

Machine learning for the prediction of antimicrobial stewardship intervention in hospitalized patients receiving broad-spectrum agents

OBJECTIVE

A significant proportion of inpatient antimicrobial prescriptions are inappropriate. Post-prescription review with feedback has been shown to be an effective means of reducing inappropriate antimicrobial use. However, implementation is resource intensive. Our aim was to evaluate the performance of traditional statistical models and machine-learning models designed to predict which patients receiving broad-spectrum antibiotics require a stewardship intervention.

METHODS

We performed a single-center retrospective cohort study of inpatients who received an antimicrobial tracked by the antimicrobial stewardship program. Data were extracted from the electronic medical record and were used to develop logistic regression and boosted-tree models to predict whether antibiotic therapy required stewardship intervention on any given day as compared to the criterion standard of note left by the antimicrobial stewardship team in the patient's chart. We measured the performance of these models using area under the receiver operating characteristic curves (AUROC), and we evaluated it using a hold-out validation cohort.

RESULTS

Both the logistic regression and boosted-tree models demonstrated fair discriminatory power with AUROCs of 0.73 (95% confidence interval [CI], 0.69-0.77) and 0.75 (95% CI, 0.72-0.79), respectively (P = .07). Both models demonstrated good calibration. The number of patients that would need to be reviewed to identify 1 patient who required stewardship intervention was high for both models (41.7-45.5 for models tuned to a sensitivity of 85%).

CONCLUSIONS

Complex models can be developed to predict which patients require a stewardship intervention. However, further work is required to develop models with adequate discriminatory power to be applicable to real-world antimicrobial stewardship practice.

Improving the Quality of Hospital Antibiotic Use: Impact on Multidrug-Resistant Bacterial Infections in Children

Antimicrobial resistance (AMR) is considered a rapidly growing global public health emergency. Neonates and children are among patients for whom antibiotics are largely prescribed and for whom the risk of AMR development is high. The phenomenon of increasing AMR has led to the need to develop measures aimed at the rational and effective use of the available drugs also in children and antimicrobial stewardship (AS), which is one of the measures that in adults has showed the highest efficacy in reducing antibiotic abuse and misuse, appears as an attractive approach. The aim of this manuscript is to analyze the basic principles and strategies of pediatric AS. To this end, we searched in PubMed articles published in years 2000 to 2019 containing "antimicrobial resistance," "antibiotic use," "antimicrobial stewardship," and "children" or "pediatric" as keywords. Our review showed that the balance between multi-resistant organisms and new antimicrobials is extremely precarious. The AS tools are the most important weapon at our disposal to stem the phenomenon. Careful monitoring of prescriptions, continuous training of prescribing physicians and collaboration with highly qualified multidisciplinary staff, creation of local and national guidelines, use of rapid diagnostic tests, technological means of support, and research activities by testing new broad-spectrum antibiotics are mandatory. However, all of these measures must be supported by adequate investment by national and international health organizations. Only by making AS daily practice, through the use of financial resources and dedicated staff, we can fight AMR to ensure safe and effective care for our young patients.

Antimicrobial Stewardship Programs Are Required in a Department of Surgery: "How" Is the Question A Quasi-Experimental Study: Results after Three Years

Objective: Our aim was to describe our antimicrobial stewardship program and the methodology based on the results in a surgical department. Methods: Our study was a quasi-experimental study conducted from January 1, 2009, through September 30, 2017. The site was the General and Digestive Surgery Department in a public primary referral center, the University Hospital of Getafe (Madrid, Spain). We implemented the antimicrobial stewardship program following a prospective audit and feedback model, with a surgeon incorporated into the manaagement group. We studied the deaths and 30-day re-admission rates, length of stay, prevalence of gram-negative bacilli, meropenem resistance, and days of treatment with meropenem. Results: After three years of the program, we recorded a significant decrease in Pseudomonas aeruginosa prevalence, a significant increase in Klebsiella pneumoniae prevalence, a decrease in meropenem resistance, and a reduction in meropenem days of treatment. Conclusions: Antimicrobial stewardship programs have a desirable effect on patients. In our experience, the program team should be led by a staff from the particular department. When human resources are limited, the sustainability, efficiency, and effectiveness of interventions are feasible only with adequate computer support. Finally, but no less important, the necessary feedback between the prescribers and the team must be based on an ad hoc method such as that provided by statistical control charts, a median chart in our study.

The effect of an antimicrobial stewardship programme in two intensive care units of a teaching hospital: an interrupted time series analysis

OBJECTIVES

To evaluate the effect of an antimicrobial stewardship programme in two intensive care units (ICUs) of a teaching hospital.

METHODS

Between January 2017 and June 2018 we conducted a prospective, interventional, interrupted time-series study, based on Prospective Audit and Feedback in two ICUs of an acute-care teaching hospital. The primary outcomes were the difference in the antibiotic consumption, and the incidence of bloodstream infections (BSI) caused by multidrug-resistant (MDR) organisms. The secondary outcomes included the hospital mortality rate, the mean length of stay and the antibiotic expense.

RESULTS

During the study, 231 audits were performed, evaluating 693 antibiotic prescriptions. The programme led to a global reduction in antibiotic consumption, with a change in level (CL) of -324.8 defined daily doses (DDD)/100 patient-days (PD), p 0.04, and particularly in the use of fluoroquinolone: (CL: -63.48 DDD/100 PD, p < 0.001). A non-significant reduction was obtained for the consumption of carbapenems (CL: -34.7 DDD/100 PD, p 0.25) and third- and fourth-generation cephalosporins (CL: -27.3 DDD/100 PD, p 0.102). Furthermore, we registered a significant decrease in all BSI (CL: -5.8 events/100 PD, p 0.026) and in BSI due to MDR Gram-negative organisms (CL: -2.96 events/100 PD, p 0.043). No difference was observed in the hospital mortality and length of stay.

CONCLUSIONS

Our study demonstrated that implementation of an antimicrobial stewardship programme in two ICUs of a teaching hospital induced a significant reduction in antibiotic consumption and in the incidence of BSI due to MDR Gram-negative organisms, without any impact on the mortality rate.

Feasibility of Core Antimicrobial Stewardship Interventions in Community Hospitals

Importance

The feasibility of core Infectious Diseases Society of America-recommended antimicrobial stewardship interventions in community hospitals is unknown.

Objective

To determine the feasibility and results of implementing 2 core stewardship intervention strategies in community hospitals.

Design, Setting, and Participants

Three-stage, multicenter, prospective nonrandomized clinical trial with crossover design. The setting was 4 community hospitals in North Carolina (median bed size, 305; range, 102-425). Participants were all patients receiving targeted study antibacterial agents or alternative, nonstudy antibacterial agents. The study dates were October 2014 through October 2015. All statistical analyses were completed as of October 2016.

Interventions

Two antimicrobial stewardship strategies targeted vancomycin hydrochloride, piperacillin-tazobactam, and the antipseudomonal carbapenems on formulary at the study hospitals: (1) modified preauthorization (PA), in which the prescriber had to receive pharmacist approval for continued use of the antibiotic after the first dose, and (2) postprescription audit and review (PPR), in which the pharmacist would engage the prescriber about antibiotic appropriateness after 72 hours of therapy. Two hospitals performed modified PA for 6 months, then PPR for 6 months after a 1-month washout. The other 2 hospitals performed the reverse.

Main Outcomes and Measures

The primary outcome was the feasibility of implementing the interventions, determined by (1) approval by hospital administration and committees at each study hospital; (2) completion of pharmacist training; (3) initiation and implementation as determined by number, type, and outcomes of interventions performed; and (4) time required for interventions. Secondary outcomes included antimicrobial use (days of therapy) compared with matched historical periods and length of hospitalization.

Results

A total of 2692 patients (median age, 65 years; interquartile range, 53-76 years) underwent a study intervention; 1413 (52.5%) were female, 1323 (49.1%) were white, and 1047 (38.9%) were African American. Intervention approvals took a median of 95 days (range, 56-119 days); during these discussions, strict PA was deemed not feasible. Instead, the modified PA intervention was used throughout the study. Pharmacists performed 1456 modified PA interventions (median per hospital, 350 [range, 129-628]) and 1236 PPR interventions (median per hospital, 298 [range, 273-366]). Study antimicrobials were determined to be inappropriate 2 times as often during the PPR period (41.0% [435 of 1060] vs 20.4% [253 of 1243]; P < .001). Pharmacists recommended dose change more often during the modified PA intervention (15.9% [232 of 1456] vs 9.6% [119 of 1236]; P < .001) and de-escalation during PPR (29.1% [360 of 1236] vs 13.0% [190 of 1456]; P < .001). The median time dedicated to the stewardship interventions varied by hospital (range of median hours per week, 5-19). Overall antibiotic use decreased during PPR compared with historical controls (mean [SD] days of therapy per 1000 patient-days, 925.2 [109.8] vs 965.3 [109.4]; mean difference, -40.1; 95% CI, -71.7 to -8.6), but not during modified PA (mean [SD] days of therapy per 1000 patient-days, 931.0 [102.0] vs 926.6 [89.7]; mean difference, 4.4; 95% CI, -55.8 to 64.7).

Conclusions and Relevance

Strict PA was not feasible in the study hospitals. In contrast, PPR was a feasible and effective strategy for antimicrobial stewardship in settings with limited resources and expertise.

Trial Registration

ClinicalTrials.gov identifier: NCT02212808.

Challenges and opportunities for antimicrobial stewardship in resource-rich and resource-limited countries

Introduction: Inappropriate prescription practices, patient and provider knowledge and attitudes, variable availability of diagnostic and surveillance systems, and the unrestricted use of antimicrobials in animals and plants are contributory factors to the global crisis of antimicrobial resistance (AMR). Areas covered: Notwithstanding that interventions to revert AMR should be tailored to the socio-politico-economic landscape, there is a global consensus for the implementation and enhancement of antimicrobial stewardship strategies. Yet the implementation of Antimicrobial Stewardship Programs (ASPs) remains relatively limited within healthcare settings and faces complex challenges in resource-limited countries. The current review summarizes the limitations of current ASPs, translation challenges in resource-limited countries, and potential solutions. Expert opinion: Suboptimal ASP implementation in hospitals is multifactorial. Restriction of antimicrobial use should be informed by risk-benefit analyses, including the potential for substitute prescribing, and displacement of selection pressures. Thresholds in population use of antibiotics above which AMR increases may provide quantitative targets for ASPs. Horizontal and vertical collaborations involving policymakers and the general public are of paramount importance. While impactful prescribing changes require sustained engagement of the public and health-care professionals, we warn against over-estimating the benefits of behavioral interventions. We advocate for population-level stewardship interventions in addition to investment in structural factors that will aid ASP implementation.

Antibiotic Review Kit for Hospitals (ARK-Hospital): study protocol for a stepped-wedge cluster-randomised controlled trial

BACKGROUND

To ensure patients continue to get early access to antibiotics at admission, while also safely reducing antibiotic use in hospitals, one needs to target the continued need for antibiotics as more diagnostic information becomes available. UK Department of Health guidance promotes an initiative called 'Start Smart then Focus': early effective antibiotics followed by active 'review and revision' 24-72 h later. However in 2017, < 10% of antibiotic prescriptions were discontinued at review, despite studies suggesting that 20-30% of prescriptions could be stopped safely.

METHODS/DESIGN

Antibiotic Review Kit for Hospitals (ARK-Hospital) is a complex 'review and revise' behavioural intervention targeting healthcare professionals involved in antibiotic prescribing or administration in inpatients admitted to acute/general medicine (the largest consumers of non-prophylactic antibiotics in hospitals). The primary study objective is to evaluate whether ARK-Hospital can safely reduce the total antibiotic burden in acute/general medical inpatients by at least 15%. The primary hypotheses are therefore that the introduction of the behavioural intervention will be non-inferior in terms of 30-day mortality post-admission (relative margin 5%) for an acute/general medical inpatient, and superior in terms of defined daily doses of antibiotics per acute/general medical admission (co-primary outcomes). The unit of observation is a hospital organisation, a single hospital or group of hospitals organised with one executive board and governance framework (National Health Service trusts in England; health boards in Northern Ireland, Wales and Scotland). The study comprises a feasibility study in one organisation (phase I), an internal pilot trial in three organisations (phase II) and a cluster (organisation)-randomised stepped-wedge trial (phase III) targeting a minimum of 36 organisations in total. Randomisation will occur over 18 months from November 2017 with a further 12 months follow-up to assess sustainability. The behavioural intervention will be delivered to healthcare professionals involved in antibiotic prescribing or administration in adult inpatients admitted to acute/general medicine. Outcomes will be assessed in adult inpatients admitted to acute/general medicine, collected through routine electronic health records in all patients.

DISCUSSION

ARK-Hospital aims to provide a feasible, sustainable and generalisable mechanism for increasing antibiotic stopping in patients who no longer need to receive them at 'review and revise'.

TRIAL REGISTRATION

ISRCTN Current Controlled Trials, ISRCTN12674243 . Registered on 10 April 2017.

Intervention and Acceptance Rates Support Handshake-Stewardship Strategy

We instituted a new antimicrobial stewardship approach that involves review of all antimicrobial agents and communication of interventions in person by a pharmacist-physician team termed handshake stewardship. The acceptance rate in this study was 86%, intervention rates were higher with a physician, and interventions on antibiotics not reviewed by other strategies were made frequently.

Threatened efficiency not autonomy: Prescriber perceptions of an established pediatric antimicrobial stewardship program

BACKGROUND

Implementing antimicrobial stewardship programs (ASPs) can be challenging due to prescriber resistance. Although barriers to implementing new ASPs have been identified, little is known about how prescribers perceive established programs. This information is critical to promoting the sustainability of ASPs.

OBJECTIVE

To identify how prescribers perceive an established pediatric inpatient ASP that primarily utilizes prior authorization.

METHODS

We conducted a cross-sectional survey administered from February through June 2017 in a large children's hospital. The survey contained closed- and open-ended questions. Descriptive statistics and thematic content analysis approaches were used to analyze responses.

RESULTS

Of 394 prescribers invited, 160 (41%) responded. Prescribers had an overall favorable impression of the ASP, believing that it improves the quality of care (92.4% agree) and takes their judgment seriously (73.8%). The most common criticism of the ASP was that it threatened efficiency (26.0% agreed). In addition, 68.7% of respondents reported occasionally engaging in workarounds. Analysis of 133 free-text responses revealed that prescribers perceived that interacting with the ASP involved too many phone calls, caused communication breakdowns with the dispensing pharmacy, and led to gaps between approval and dispensing of antibiotics. Reasons given for workarounds included not wanting to change therapy that appears to be working, consultant disagreement with ASP recommendations, and the desire to do everything possible for patients.

CONCLUSIONS

Prescribers had a generally favorable opinion of an established ASP but found aspects to be inefficient. They reported engaging in workarounds occasionally for social and emotional reasons. Established ASPs should elicit feedback from frontline prescribers to optimize program impact.

Impact of an Unsolicited, Standardized Form-Based Antimicrobial Stewardship Intervention to Improve Guideline Adherence in the Management of Staphylococcus aureus Bacteremia

Background

Antimicrobial stewardship programs (ASPs) improve Staphylococcus aureus bacteremia (SAB) management. The objective of the current study was to evaluate the effect of unsolicited prospective audit and feedback (PAF) using a standardized SAB bundle form on the management of SAB.

Methods

Multicenter, pre-post quasi-experimental study of inpatients with SAB. The ASP developed an evidence-based SAB management bundle that included recommendations for infectious diseases consultation, blood culture clearance, appropriate empiric and definitive therapy, echocardiography, adequate treatment duration, and source control where applicable. ASP pharmacists performed PAF using a standardized form outlining bundle components. The primary outcome was bundle component adherence. Secondary outcomes were length of stay, 30-day readmission rate, and in-hospital and 30-day mortality rates.

Results

A total of 199 patients were included (preintervention group, 62; intervention group, 137). Bundle implementation with PAF resulted in significant improvements in infectious diseases consultation (56.5% in preintervention vs 93.4% in intervention group), appropriate definitive antibiotic therapy (83.9% vs 99.3%), ordering echocardiography (72.6% vs 95.6%), and adequate treatment duration (87.0% vs 100%) (all P < .001). Overall bundle adherence increased by 43.8% (P < .001). Readmission and 30-day mortality rates decreased, but this difference did not reach statistical significance.

Conclusions

Unsolicited PAF using a standardized SAB management bundle significantly improved adherence to evidence-based recommendations. This simple yet effective ASP-driven intervention can ensure consistent management of a highly morbid infection.

Febrile Neutropenia in Transplant Recipients

Febrile neutropenic patients are at increased risk of developing infections. During the initial stages of neutropenia, most of these infections are bacterial. The spectrum of bacterial infections depends to some extent on whether or not patients receive antimicrobial prophylaxis when neutropenic. Since most transplant recipients do, Gram-positive organisms predominate, due to the fact prophylaxis is directed primarily against Gram-negative organisms. Staphylococcus species (often methicillin-resistant), Streptococcus species (viridans group streptococci, beta-hemolytic streptococci), and Enterococcus species (including vancomycin-resistant strains) are isolated most often. Therefore, potent empiric Gram-positive coverage is recommended by many in this setting. Escherichia coli, Pseudomonas aeruginosa, and Klebsiella species are the most common Gram-negative pathogens isolated. Non-fermentative Gram-negative bacilli (Stenotrophomonas maltophilia, Acinetobacter species) are emerging as important pathogens. Many of these organisms acquire multiple mechanisms of resistance that render them multidrug resistant. The administration of prompt, broad-spectrum, empiric, antimicrobial therapy is essential and is generally based on local epidemiology and susceptibility/resistance patterns. Response rate to the initial regimen is generally in the range of 75–85%. Fungal infections develop in patients with prolonged neutropenia (greater than 7–10 days). Candida species and Aspergillus species are the predominant fungal pathogens, although many other fungi are opportunistic pathogens in this setting. Fungal infections are seldom documented microbiologically or on histopathology, and the administration of empiric antifungal therapy, when such infections are suspected, is the norm. Therapy is often prolonged, and outcomes are still suboptimal. The importance of infection control and antimicrobial stewardship cannot be overemphasized.

Study protocol for a multicentre, cluster randomised, superiority trial evaluating the impact of computerised decision support, audit and feedback on antibiotic use: the COMPuterized Antibiotic Stewardship Study (COMPASS)

INTRODUCTION

Inappropriate use of antimicrobials in hospitals contributes to antimicrobial resistance. Antimicrobial stewardship (AMS) interventions aim to improve antimicrobial prescribing, but they are often resource and personnel intensive. Computerised decision supportsystems (CDSSs) seem a promising tool to improve antimicrobial prescribing but have been insufficiently studied in clinical trials.

METHODS AND ANALYSIS

The COMPuterized Antibiotic Stewardship Study trial, is a publicly funded, open-label, cluster randomised, controlled superiority trial which aims to determine whether a multimodal CDSS intervention integrated in the electronic health record (EHR) reduces overall antibiotic exposure in adult patients hospitalised in wards of two secondary and one tertiary care centre in Switzerland compared with 'standard-of-care' AMS. Twenty-four hospital wards will be randomised 1:1 to either intervention or control, using a 'pair-matching' approach based on baseline antibiotic use, specialty and centre. The intervention will consist of (1) decision support for the choice of antimicrobial treatment and duration of treatment for selected indications (based on indication entry), (2) accountable justification for deviation from the local guidelines (with regard to the choice of molecules and duration), (3) alerts for self-guided re-evaluation of treatment on calendar day 4 of antimicrobial therapy and (4) monthly ward-level feedback of antimicrobial prescribing indicators. The primary outcome will be the difference in overall systemic antibiotic use measured in days of therapy per admission based on administration data recorded in the EHR over the whole intervention period (12 months), taking into account clustering. Secondary outcomes include qualitative and quantitative antimicrobial use indicators, economic outcomes and clinical, microbiological and patient safety indicators.

ETHICS AND DISSEMINATION

Ethics approval was obtained for all participating sites (Comission Cantonale d'Éthique de la Recherche (CCER)2017-00454). The results of the trial will be submitted for publication in a peer-reviewed journal. Further dissemination activities will be presentations/posters at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT03120975; Pre-results.

Assessing the impact of antibiotic stewardship program elements on antibiotic use across acute-care hospitals: an observational study

OBJECTIVES

Antibiotic use varies widely between hospitals, but the influence of antimicrobial stewardship programs (ASPs) on this variability is not known. We aimed to determine the key structural and strategic aspects of ASPs associated with differences in risk-adjusted antibiotic utilization across facilities.

DESIGN

Observational study of acute-care hospitals in Ontario, Canada METHODS: A survey was sent to hospitals asking about both structural (8 elements) and strategic (32 elements) components of their ASP. Antibiotic use from hospital purchasing data was acquired for January 1 to December 31, 2014. Crude and adjusted defined daily doses per 1,000 patient days, accounting for hospital and aggregate patient characteristics, were calculated across facilities. Rate ratios (RR) of defined daily doses per 1,000 patient days were compared for hospitals with and without each antimicrobial stewardship element of interest.

RESULTS

Of 127 eligible hospitals, 73 (57%) participated in the study. There was a 7-fold range in antibiotic use across these facilities (min, 253 defined daily doses per 1,000 patient days; max, 1,872 defined daily doses per 1,000 patient days). The presence of designated funding or resources for the ASP (RRadjusted, 0·87; 95% CI, 0·75-0·99), prospective audit and feedback (RRadjusted, 0·80; 95% CI, 0·67-0·96), and intravenous-to-oral conversion policies (RRadjusted, 0·79; 95% CI, 0·64-0·99) were associated with lower risk-adjusted antibiotic use.

CONCLUSIONS

Wide variability in antibiotic use across hospitals may be partially explained by both structural and strategic ASP elements. The presence of funding and resources, prospective audit and feedback, and intravenous-to-oral conversion should be considered priority elements of a robust ASP.

Outcomes of multisite antimicrobial stewardship programme implementation with a shared clinical decision support system

Background

Studies evaluating antimicrobial stewardship programmes (ASPs) supported by computerized clinical decision support systems (CDSSs) have predominantly been conducted in single site metropolitan hospitals.

Objectives

To examine outcomes of multisite ASP implementation supported by a centrally deployed CDSS.

Methods

An interrupted time series study was conducted across five hospitals in New South Wales, Australia, from 2010 to 2014. Outcomes analysed were: effect of the intervention on targeted antimicrobial use, antimicrobial costs and healthcare-associated Clostridium difficile infection (HCA-CDI) rates. Infection-related length of stay (LOS) and standardized mortality ratios (SMRs) were also assessed.

Results

Post-intervention, antimicrobials targeted for increased use rose from 223 to 293 defined daily doses (DDDs)/1000 occupied bed days (OBDs)/month (+32%, P  <   0.01). Conversely, antimicrobials targeted for decreased use fell from 254 to 196 DDDs/1000 OBDs/month (-23%; P  <   0.01). These effects diminished over time. Antimicrobial costs decreased initially (-AUD$64551/month; P  <   0.01), then increased (+AUD$7273/month; P  <   0.01). HCA-CDI rates decreased post-intervention (-0.2 cases/10 000 OBDs/month; P  <   0.01). Proportional LOS reductions for key infections (respiratory from 4.8 to 4.3 days, P  <   0.01; septicaemia 6.8 to 6.1 days, P  <   0.01) were similar to background LOS reductions (2.1 to 1.9 days). Similarly, infection-related SMRs (observed/expected deaths) decreased (respiratory from 1.1 to 0.75; septicaemia 1.25 to 0.8; background rate 1.19 to 0.90.

Conclusions

Implementation of a collaborative multisite ASP supported by a centrally deployed CDSS was associated with changes in targeted antimicrobial use, decreased antimicrobial costs, decreased HCA-CDI rates, and no observable increase in LOS or mortality. Ongoing targeted interventions are suggested to promote sustainability.

Protocol to disseminate a hospital-site controlled intervention using audit and feedback to implement guidelines concerning inappropriate treatment of asymptomatic bacteriuria

BACKGROUND

Antimicrobial stewardship to combat the spread of antibiotic-resistant bacteria has become a national priority. This project focuses on reducing inappropriate use of antimicrobials for asymptomatic bacteriuria (ASB), a very common condition that leads to antimicrobial overuse in acute and long-term care. We previously conducted a successful intervention, entitled "Kicking Catheter Associated Urinary Tract Infection (CAUTI): the No Knee-Jerk Antibiotics Campaign," to decrease guideline-discordant ordering of urine cultures and antibiotics for ASB. The current objective is to facilitate implementation of a scalable version of the Kicking CAUTI campaign across four geographically diverse Veterans Health Administration facilities while assessing what aspects of an antimicrobial stewardship intervention are essential to success and sustainability.

METHODS

This project uses an interrupted time series design with four control sites. The two main intervention tools are (1) an evidence-based algorithm that distills the guidelines into a streamlined clinical pathway and (2) case-based audit and feedback to train clinicians to use the algorithm. Our conceptual framework for the development and implementation of this intervention draws on May's General Theory of Implementation. The intervention is directed at providers in acute and long-term care, and the goal is to reduce inappropriate screening for and treatment of ASB in all patients and residents, not just those with urinary catheters. The start-up for each facility consists of centrally-led phone calls with local site champions and baseline surveys. Case-based audit and feedback will begin at a given site after the start-up period and continue for 12 months, followed by a sustainability assessment. In addition to the clinical outcomes, we will explore the relationship between the dose of the intervention and clinical outcomes.

DISCUSSION

This project moves from a proof-of-concept effectiveness study to implementation involving significantly more sites, and uses the General Theory of Implementation to embed the intervention into normal processes of care with usual care providers. Aspects of implementation that will be explored include dissemination, internal and external facilitation, and organizational partnerships. "Less is More" is the natural next step from our prior successful Kicking CAUTI intervention, and has the potential to improve patient care while advancing the science of implementation.

Feasibility and applicability of antimicrobial stewardship in immunocompromised patients

PURPOSE OF REVIEW

Antimicrobial stewardship is the primary intervention in the battle against antimicrobial resistance, but clinicians do not always apply many key antimicrobial stewardship principles to patients with significant immune defects due to lack of data and fear of bad outcomes. We review evidence regarding the application of stewardship principles to immunocompromised patients, with a focus on solid organ and hematopoietic stem cell transplant recipients.

RECENT FINDINGS

Antimicrobial stewardship programs (ASPs), targeting immunocompromised patient populations such as oncology and transplant, are gaining traction. Emerging literature suggests that several stewardship interventions can be adapted to immunocompromised hosts and improve antimicrobial utilization, but data supporting improved outcomes is very limited.

SUMMARY

The application of antimicrobial stewardship principles to immunocompromised patients is feasible, necessary, and urgent. As antimicrobial stewardship programs gain momentum across a diverse range of healthcare settings more immunocompromised patients will fall under their purview. It is imperative that centers applying antimicrobial stewardship principles share their experience and establish collaborative research efforts to advance our knowledge base in applying antimicrobial stewardship initiatives to immunocompromised host populations, both in terms of programmatic success and patient outcomes.

What Is the More Effective Antibiotic Stewardship Intervention: Preprescription Authorization or Postprescription Review With Feedback?

Background

The optimal approach to conducting antibiotic stewardship interventions has not been defined. We compared days of antibiotic therapy (DOT) using preprescription authorization (PPA) vs postprescription review with feedback (PPRF) strategies.

Methods

A quasi-experimental, crossover trial comparing PPA and PPRF for adult inpatients prescribed any antibiotic was conducted. For the first 4 months, 2 medicine teams were assigned to the PPA arm and the other 2 teams to the PPRF arm. The teams were then assigned to the alternate arm for an additional 4 months. Appropriateness of antibiotic use was adjudicated by at least 2 infectious diseases-trained clinicians and according to institutional guidelines.

Results

There were 2686 and 2693 patients admitted to the PPA and PPRF groups, with 29% and 27% of patients prescribed antibiotics, respectively. Initially, antibiotic DOTs remained relatively unchanged in the PPA arm. When changed to the PPRF arm, antibiotic use decreased (-2.45 DOT per 1000 patient-days [PD]). In the initial PPRF arm, antibiotic use decreased (slope of -5.73 DOT per 1000 PD) but remained constant when changed to the PPA arm. Median patient DOTs in the PPA and PPRF arms were 8 and 6 DOT per 1000 PD, respectively (P = .03). Antibiotic therapy was guideline-noncompliant in 34% and 41% of patients on days 1 and 3 in the PPA group (P < .01) and in 57% and 36% of patients on days 1 and 3 in the PPRF group (P = .03).

Conclusions

PPRF may have more of an impact on decreasing antibiotic DOTs compared with PPA. This information may be useful for institutions without sufficient resources to incorporate both stewardship approaches.

Association of Adverse Events With Antibiotic Use in Hospitalized Patients

IMPORTANCE

Estimates of the incidence of overall antibiotic-associated adverse drug events (ADEs) in hospitalized patients are generally unavailable.

OBJECTIVE

To describe the incidence of antibiotic-associated ADEs for adult inpatients receiving systemic antibiotic therapy.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort of adult inpatients admitted to general medicine wards at an academic medical center.

EXPOSURES

At least 24 hours of any parenteral or oral antibiotic therapy.

MAIN OUTCOMES AND MEASURES

Medical records of 1488 patients were examined for 30 days after antibiotic initiation for the development of the following antibiotic-associated ADEs: gastrointestinal, dermatologic, musculoskeletal, hematologic, hepatobiliary, renal, cardiac, and neurologic; and 90 days for the development of Clostridium difficile infection or incident multidrug-resistant organism infection, based on adjudication by 2 infectious diseases trained clinicians.

RESULTS

In 1488 patients, the median age was 59 years (interquartile range, 49-69 years), and 758 (51%) participants were female. A total of 298 (20%) patients experienced at least 1 antibiotic-associated ADE. Furthermore, 56 (20%) non-clinically indicated antibiotic regimens were associated with an ADE, including 7 cases of C difficile infection. Every additional 10 days of antibiotic therapy conferred a 3% increased risk of an ADE. The most common ADEs were gastrointestinal, renal, and hematologic abnormalities, accounting for 78 (42%), 45 (24%), and 28 (15%) 30-day ADEs, respectively. Notable differences were identified between the incidence of ADEs associated with specific antibiotics.

CONCLUSIONS AND RELEVANCE

Although antibiotics may play a critical role when used appropriately, our findings underscore the importance of judicious antibiotic prescribing to reduce the harm that can result from antibiotic-associated ADEs.

Acceptance of Pharmacist-Driven Antimicrobial Stewardship Recommendations With Differing Levels of Physician Involvement in a Children's Hospital

This prospective interventional study assessed whether a pharmacist-physician team in a setting where physician support is not provided for daily antimicrobial stewardship (AS) activities would improve later acceptance of pharmacist recommendations once multidisciplinary efforts stopped and the pharmacist again worked alone. This was measured by AS recommendation acceptance rate during 3 study phases wherein AS recommendations were provided by a pharmacist alone (Phase 1), a pharmacist and a physician together (Phase 2), and then a pharmacist alone again (Phase 3). Recommendations were well accepted across all study phases with no differences in recommendation appropriateness or patient clinical outcomes. Prescribers were significantly ( P = .045) more likely to accept recommendations to de-escalate treatment during Phase 3 than during Phase 1. Independently pharmacist-driven AS efforts were generally successful, and recommendations for antimicrobial de-escalation were better accepted after the involvement of an infectious diseases physician.

Antibiotic use and clinical outcomes in the acute setting under management by an infectious diseases acute physician versus other clinical teams: a cohort study

OBJECTIVES

To assess the magnitude of difference in antibiotic use between clinical teams in the acute setting and assess evidence for any adverse consequences to patient safety or healthcare delivery.

DESIGN

Prospective cohort study (1 week) and analysis of linked electronic health records (3 years).

SETTING

UK tertiary care centre.

PARTICIPANTS

All patients admitted sequentially to the acute medical service under an infectious diseases acute physician (IDP) and other medical teams during 1 week in 2013 (n=297), and 3 years 2012-2014 (n=47 585).

PRIMARY OUTCOME MEASURE

Antibiotic use in days of therapy (DOT): raw group metrics and regression analysis adjusted for case mix.

SECONDARY OUTCOME MEASURES

30-day all-cause mortality, treatment failure and length of stay.

RESULTS

Antibiotic use was 173 vs 282 DOT/100 admissions in the IDP versus non-IDP group. Using case mix-adjusted zero-inflated Poisson regression, IDP patients were significantly less likely to receive an antibiotic (adjusted OR=0.25 (95% CI 0.07 to 0.84), p=0.03) and received shorter courses (adjusted rate ratio (RR)=0.71 (95% CI 0.54 to 0.93), p=0.01). Clinically stable IDP patients of uncertain diagnosis were more likely to have antibiotics held (87% vs 55%; p=0.02). There was no significant difference in treatment failure or mortality (adjusted p>0.5; also in the 3-year data set), but IDP patients were more likely to be admitted overnight (adjusted OR=3.53 (95% CI 1.24 to 10.03), p=0.03) and have longer length of stay (adjusted RR=1.19 (95% CI 1.05 to 1.36), p=0.007).

CONCLUSIONS

The IDP-led group used 30% less antibiotic therapy with no adverse clinical outcome, suggesting antibiotic use can be reduced safely in the acute setting. This may be achieved in part by holding antibiotics and admitting the patient for observation rather than prescribing, which has implications for costs and hospital occupancy. More information is needed to indicate whether any such longer admission will increase or decrease risk of antibiotic-resistant infections.