Evaluation of the Infectious Diseases Society of America's Core Antimicrobial Stewardship Curriculum for Infectious Diseases Fellows.

BACKGROUND: Antimicrobial stewardship (AS) programs are required by Centers for Medicare and Medicaid Services and should ideally have infectious diseases (ID) physician involvement; however, only 50% of ID fellowship programs have formal AS curricula. The Infectious Diseases Society of America (IDSA) formed a workgroup to develop a core AS curriculum for ID fellows. Here we study its impact. METHODS: ID program directors and fellows in 56 fellowship programs were surveyed regarding the content and effectiveness of their AS training before and after implementation of the IDSA curriculum. Fellows' knowledge was assessed using multiple-choice questions. Fellows completing their first year of fellowship were surveyed before curriculum implementation ("pre-curriculum") and compared to first-year fellows who complete the curriculum the following year ("post-curriculum"). RESULTS: Forty-nine (88%) program directors and 105 (67%) fellows completed the pre-curriculum surveys; 35 (64%) program directors and 79 (50%) fellows completed the post-curriculum surveys. Prior to IDSA curriculum implementation, only 51% of programs had a "formal" curriculum. After implementation, satisfaction with AS training increased among program directors (16% to 68%) and fellows (51% to 68%). Fellows' confidence increased in 7/10 AS content areas. Knowledge scores improved from a mean of 4.6 to 5.1 correct answers of 9 questions (P = .028). The major hurdle to curriculum implementation was time, both for formal teaching and for e-learning. CONCLUSIONS: Effective AS training is a critical component of ID fellowship training. The IDSA Core AS Curriculum can enhance AS training, increase fellow confidence, and improve overall satisfaction of fellows and program directors.

Investing in the Future: A Role for Professional Societies to Prepare the Next Generation of Healthcare Leaders Through Curriculum Development and Dissemination.

Professional societies serve many functions that benefit constituents; however, few professional societies have undertaken the development and dissemination of formal, national curricula to train the future workforce while simultaneously addressing significant healthcare needs. The Infectious Diseases Society of America (IDSA) has developed 2 curricula for the specific purpose of training the next generation of clinicians to ensure the future infectious diseases (ID) workforce is optimally trained to lead antimicrobial stewardship programs and equipped to meet the challenges of multidrug resistance, patient safety, and healthcare quality improvement. A core curriculum was developed to provide a foundation in antimicrobial stewardship for all ID fellows, regardless of career path. An advanced curriculum was developed for ID fellows specifically pursuing a career in antimicrobial stewardship. Both curricula will be broadly available in the summer of 2021 through the IDSA website.

Antimicrobial stewardship education in US colleges and schools of pharmacy.

Background: Pharmacists are key members of antimicrobial stewardship (AS) teams. It is unknown if and how US colleges and schools of pharmacy incorporate AS into their Doctor of Pharmacy (PharmD) curricula. Methods: This study was a cross-sectional, multicentre, electronic survey distributed to infectious diseases faculty or department chairs of 137 accredited and candidate-status PharmD programmes. Results: One hundred and sixteen programmes participated, representing an 84.7% response rate. AS education was integrated into the required didactic, elective didactic and experiential education components of the curricula in 79 (68.1%), 43 (37.1%) and 97 (83.6%) PharmD programmes, respectively. The most common AS topics in required and elective didactic curricula were AS definitions, principles and purpose (98.7% and 86.0%) and the pharmacist's role in AS (93.7% and 83.7%). In the required and elective didactic curricula, lecture (93.7% and 86.0%) and case-based instruction (57.0% and 83.7%) were the most common instructional methods. For experiential education, the pharmacist's role in AS (96.9%), de-escalation of antimicrobials (96.9%) and antimicrobial dose optimization (95.9%) were the most common AS topics. PharmD programmes employing a faculty member who specializes in AS were more likely to offer AS experiential education than programmes without AS faculty (88.1% versus 71.9%, P = 0.049). Conclusions: Integration of AS education in US PharmD curricula is variable and there are considerable differences in the AS activities and topics delivered. PharmD programmes should attempt to expose students to AS education to prepare future pharmacists for AS practice. Efforts should be made to incorporate interprofessional collaboration into AS education.

Executive Summary: Implementing an Antibiotic Stewardship Program: Guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America.

Evidence-based guidelines for implementation and measurement of antibiotic stewardship interventions in inpatient populations including long-term care were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. The panel included clinicians and investigators representing internal medicine, emergency medicine, microbiology, critical care, surgery, epidemiology, pharmacy, and adult and pediatric infectious diseases specialties. These recommendations address the best approaches for antibiotic stewardship programs to influence the optimal use of antibiotics.

Implementing an Antibiotic Stewardship Program: Guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America.

Evidence-based guidelines for implementation and measurement of antibiotic stewardship interventions in inpatient populations including long-term care were prepared by a multidisciplinary expert panel of the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. The panel included clinicians and investigators representing internal medicine, emergency medicine, microbiology, critical care, surgery, epidemiology, pharmacy, and adult and pediatric infectious diseases specialties. These recommendations address the best approaches for antibiotic stewardship programs to influence the optimal use of antibiotics.

Effect of an electronic medical record alert for severe sepsis among ED patients.

BACKGROUND: Severe sepsis and septic shock are a major health concern worldwide. The objective of this study is to determine if Severe Sepsis Best Practice Alert (SS-BPA) implementation was associated with improved processes of care and clinical outcomes among patients with severe sepsis or septic shock presenting to the emergency department (ED). METHODS: This is a single-center, before-and-after observational study. The intervention group (n = 103) consisted of adult patients presenting to the ED with severe sepsis or septic shock during a 7-month period after implementation of the SS-BPA. The control group (n = 111) consisted of patients meeting the same criteria over a prior 7-month period. The SS-BPA primarily acts by automated, real-time, algorithm-based detection of severe sepsis or septic shock via the electronic medical record system. The primary outcome was in-hospital mortality. Secondary outcomes included hospital length of stay (LOS), time to antibiotic administration, and proportion of patients who received antibiotics within the target 60 minutes. RESULTS: Time to antibiotics was significantly reduced in the SS-BPA cohort (29 vs 61.5 minutes, P < .001). In addition, there was a higher proportion of patients who received antibiotics within 60 minutes (76.7 vs 48.6%; P < .001). On multivariable analysis, in-hospital mortality was not significantly reduced in the intervention group (odds ratio, 0.64; 95% confidence interval, 0.26-1.57). Multivariable analysis of LOS indicated a significant reduction among patients in the SS-BPA cohort (geometric mean ratio, 0.66; 95% confidence interval, 0.53-0.82). CONCLUSION: Implementation of the SS-BPA for severe sepsis or septic shock among ED patients is associated with significantly improved timeliness of antibiotic administration and reduced hospital LOS.

Knowledge and attitudes of doctor of pharmacy students regarding the appropriate use of antimicrobials.

Pharmacists are key partners in antimicrobial stewardship efforts, yet their degree of education on and attitudes toward this topic during training are not well documented. An electronic survey measuring knowledge and attitudes regarding antimicrobial use and resistance was administered to graduating pharmacy students at 12 US schools of pharmacy. Of 1445 pharmacy students, 579 (40%) completed the survey. The vast majority (94%) believed that strong knowledge of antimicrobials was important for their pharmacy careers, and 89% desired more education on appropriate antimicrobial use. Most students (84%) considered their pharmacy education regarding antimicrobials useful or very useful, but there was significant variability on perceptions of preparation for most antimicrobial stewardship activities according to the students' school. The mean number of correct answers on a section of 11 knowledge questions was 5.8 (standard deviation 2.0; P value for score between schools <.001). On multivariable linear regression analysis, significant predictors of a higher knowledge score were pharmacy school attended, planned postgraduate training, completion of a clinical rotation in infectious diseases, perception of pharmacy school education as useful, use of resources to answer the knowledge questions, and use of Infectious Diseases Society of America guidelines and smartphone applications as frequent resources for learning about antimicrobials. Pharmacy students perceive antimicrobial stewardship to be an important healthcare issue and desire more education on the subject. Student perceptions of antimicrobial coursework and actual antimicrobial knowledge scores significantly varied by the school of pharmacy attended. Sharing of best practices among institutions may enhance the preparation of future pharmacists to contribute to effective antimicrobial stewardship.

Bugs and drugs - what do pharmacists need to know and what's the best way to learn it?

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

Student Performance Outcomes and Perceptions in Two Content Areas in Conventional Versus Integrated Pharmacy Curricula.

Objective. To compare student performance measures and perceptions of learning in 2 content areas, conventional and integrated pharmacy curricula, at a single institution.Methods. Prospective cohort study of pharmacy students enrolled in either conventional (cohort C) or integrated (cohort I) curricula. Summative examination performance in the neuropsychiatric and infectious diseases courses, student self-rating of confidence and comfort in integrating and applying knowledge, and performance on a delayed knowledge assessment were compared between cohorts.Results. Cohort I students performed significantly lower on summative assessments compared to cohort C (78.4±9.1 vs 84.5±8.3, respectively). Prior to the integrated course, cohort I students rated themselves as significantly less confident and comfortable in knowledge integration, application, and communication compared to cohort C students; these differences were attenuated in a follow-up survey, although some remained significant. There was no difference between cohorts in performance on objective structured clinical examinations (OSCEs) or on a delayed knowledge assessment of neuropsychiatric and infectious diseases content.Conclusion. Pharmacy students in an integrated curriculum initially performed modestly worse in summative assessments and self-assessed their baseline knowledge as lower than did students in a conventional curriculum. However, differences in self-rated knowledge decreased at follow-up, and performance of the two cohorts on OSCEs and a delayed examination was similar. As pharmacy curricula shift towards integrated models, institutions should also consider evaluating experiential performance outcomes and student motivation to fully assess the impact of these transitions.

Changes in Pharmacy Students' Self-Reported Learning Strategies Across a Four-Year Doctor of Pharmacy Program.

Objective. Few studies describe changes in students' class preparation, note-taking, and examination preparation over the course of professional school. This study aims to describe the use of these learning and study strategies by pharmacy students and to analyze changes during their education.Methods. We performed a prospective, observational cohort study of students at a single US pharmacy school from 2016-2019. Students completed an online survey on learning and study strategies at the beginning of each school year. Quantitative results were analyzed by level in pharmacy school during which the survey was completed as the primary predictor. Open-ended responses were thematically analyzed using an inductive approach.Results. We observed significant changes in strategies, including an increased use of audiovisual materials for course preparation, preference for electronic over manual notetaking, increasing use of lecture capture viewing, and increased use of peer materials in studying. Changes were generally largest between students' first (P1) and second (P2) years in pharmacy school, representing adjustments in student behaviors during the P1 year. In some cases, changes from the surveys in the P1 to P2 years were followed by a gradual return toward P1 survey levels. Three themes described students' comments: students' preferences shaped their learning strategies, their experiences guided changes in learning strategies, and they used additional strategies beyond those included in the survey items.Conclusions. Significant changes in pharmacy student study strategies occurred over the course of their education. This may represent an opportunity to promote use of more effective approaches for long-term learning.

Longitudinal study of grit among pharmacy students: Impact of cohort and professional year.

INTRODUCTION: Whether grit changes over a student's enrollment in health professions school is unknown. We aimed to measure grit across 13 cohort-years of students in a four-year doctor of pharmacy (PharmD) program. METHODS: We administered the Short Grit Scale (Grit-S) to first-year (P1), second-year (P2), third-year (P3), and fourth-year (P4) PharmD students between 2016 and 2019. There was no intervention aimed at increasing grit. RESULTS: A total of 1381 responses were recorded across 624 students (86.5% response rate). Across all graduation cohorts, Grit-S scores significantly decreased by an average of 0.087 points from P1 to P2 (P = .004), increased significantly from P2 to P3 by 0.09 points (P < .001), and nominally increased from P3 to P4 by 0.023 points (P = .45). Between cohort differences in paired Grit-S scores only differed significantly for P3 to P4 (P = .03) and P1 to P3 (P = .01) years. A mixed-effects linear regression model clustered on graduation cohort and individual student found that mean Grit-S scores in the P2 year were - 0.1 points lower than those in the P1 year (P < .001). However, differences between P3 and P1 (-0.04, P = .17) and between P4 and P1 (-0.03, P = .37) were not statistically significant. CONCLUSIONS: In the absence of a specific intervention, statistically significant changes in Grit-S scores occur over the course of a pharmacy school curriculum. The P1 year may be associated with a decline in grit, although by the P4 year Grit-S scores return to baseline.

Systematic review of drug-drug interactions between rifamycins and anticoagulant and antiplatelet agents and considerations for management.

Rifamycins (rifampin, rifabutin, and rifapentine) play an essential role in the treatment of mycobacterial and some nonmycobacterial infections. They also induce the activity of various drug transporting and metabolizing enzymes, which can impact the concentrations and efficacy of substrates. Many anticoagulant and antiplatelet (AC/AP) agents are substrates of these enzymes and have narrow therapeutic indices, leading to risks of thrombosis or bleeding when coadministered with rifamycins. The objective of this systematic review was to evaluate the effects on AC/AP pharmacokinetics, laboratory markers, and clinical safety and efficacy of combined use with rifamycins. A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidance was performed. The PubMed, Embase, and Web of Science databases were queried for English-language reports on combination use of rifamycins and AC/AP agents from database inception through August 2021. The 29 studies identified examined warfarin (n = 17), direct oral anticoagulants (DOACs) (n = 8), and antiplatelet agents (n = 4) combined with rifampin (n = 28) or rifabutin (n = 1). Eleven studies were case reports or small case series; 14 reported on pharmacokinetic or laboratory markers in healthy volunteers. Rifampin-warfarin combinations led to reductions in warfarin area under the curve (AUC) of 15%-74%, with variability by warfarin isomer and study. Warfarin dose increases of up to 3-5 times prerifampin doses were required to maintain coagulation parameters in the therapeutic range. DOAC AUCs were decreased by 20%-67%, with variability by individual agent and with rifampin versus rifabutin. The active metabolite of clopidogrel increased substantially with rifampin coadministration, whereas prasugrel was largely unaffected and ticagrelor saw decreases. Our review suggests most combinations of AC/AP agents and rifampin are problematic. Further studies are required to determine whether rifabutin or rifapentine could be safe alternatives for coadministration with AC/AP drugs.

Topical antacid therapy for capsaicin-induced dermal pain: a poison center telephone-directed study.

PURPOSE: The study aimed to assess the effects of topical antacids for treatment of capsaicin-induced dermal pain after exposure to capsaicin containing hot peppers, personal protection sprays, or topical creams. PROCEDURES: Participants of the study were California Poison Control System (CPCS) hotline callers 12 years or older with dermal pain from exposure to capsaicin-containing products or plants. Participants were instructed to apply a topical antacid and assessed for perceived pain (using a 0-10 scale) pre- and posttreatment. A positive response was defined as a sustained reduction of pain 33% or more within 30 minutes or achieving a pain score of 0 to 1. MAIN FINDINGS: Of 93 eligible patients, 64 applied antacids and had outcome data available. Patients contacted the CPCS a median of 1 hour postexposure with a median initial pain score of 7.5/10. Thirty-six (56%) were exposed to unrefined (natural) peppers and 28 (44%) to refined capsaicin (eg, capsaicin-containing cream). Before calling the CPCS, 57 (89%) attempted at least one treatment. Forty-five (70%) reported positive response to antacid treatment as a 33% reduction in pain in 30 minutes (n = 17), a reduction in pain to a score of 0 to 1 (n = 3), or both (n = 25). A 33% reduction in pain within 30 minutes was associated with exposure to refined capsaicin (odds ratio, 3.37; 95% confidence interval, 0.98-11.66). Concomitant refined capsaicin exposure and early treatment (<1 hour of symptoms) was associated with even greater odds of response (odds ratio, 5.4; 95% confidence interval, 1.4-21.2). CONCLUSION: Topical application of antacids for capsaicin-induced pain is effective, particularly in early treatment of exposure to refined capsaicin.

National estimates and predictors of prescription medication sample use in the United States, 1999-2005.

OBJECTIVES: To determine the prevalence of free medication sample use in the United States and analyze the effects of socioeconomic status and drug safety actions. DESIGN: Cross-sectional study. SETTING: United States from 1999 to 2005. PARTICIPANTS: Survey respondents representative of the civilian noninstitutionalized population. INTERVENTION: Analysis of data from the Medical Expenditure Panel Survey, a nationally representative longitudinal household survey. MAIN OUTCOME MEASURES: Identification of a medication as being provided as a sample at least once during a study year. RESULTS: An annual average of 5.1% (range 4.4% in 2005 to 5.8% in 2002) of all prescription medications were provided as a sample at least once during a year, with 18.3% of all Americans who received at least one prescription drug receiving at least one drug as a sample. On multivariate analysis, sample use was greater among young (18-30 years) non-Hispanic whites and the uninsured but had minimal independent association with income. The proportion of sample use among users of hormone replacement therapy and cyclooxygenase-2 inhibitors remained relatively constant even as total use of these drugs declined after Food and Drug Administration regulatory action. CONCLUSION: Use of medication samples is common in the U.S. population. After adjusting for health insurance, sample use was not associated with income and samples were less frequently provided to racial/ethnic minorities and to the elderly. The putative economic benefits of free samples do not appear to go to patients with the greatest financial need. Drug regulatory actions did not have a disproportionate effect on provision of drugs as samples.

A Randomized, Crossover Pilot Study of a Novel Web-Based/Mobile Platform for Collaborative Small Group Practice in Therapeutic Reasoning.

BACKGROUND AND PURPOSE: Therapeutic reasoning-the mental process of making judgments and decisions about treatment-is developed through acquisition of knowledge and application in actual or simulated experiences. Health professions education frequently uses collaborative small group work to practice therapeutic reasoning. This pilot study compared the impact of a web-based/mobile tool for collaborative case work and discussion to usual practice on student perceptions and performance on questions designed to test therapeutic knowledge and reasoning. METHODS: In a therapeutics course that includes case-based workshops, student teams of 3 to 4 were randomly assigned to usual workshop preparation (group SOAP sheet) or preparation using the Practice Improvement using Virtual Online Training (PIVOT) platform. PIVOT was also used in the workshop to review the case and student responses. The next week, groups crossed over to the other condition. Students rated favorability with the preparatory and in-workshop experiences and provided comments about the PIVOT platform via a survey. Student performance on examination items related to the 2 workshop topics was compared. RESULTS: One hundred and eleven students (94%) completed post-workshop surveys after both workshops. The majority of students (57%) preferred using the PIVOT platform for workshop collaboration. Favorability ratings for the in-workshop experience did not change significantly from first to second study week, regardless of sequence of exposure. There was no relationship between examination item scores and the workshop platform the students were exposed to for that content (P = .29). Student responses highlighted the efficiency of working independently before collaborating as a group and the ability to see other students' thought processes as valuable aspects of PIVOT. Students expressed frustration with the PIVOT user interface and the lack of anonymity when discussing their answers in the workshop. CONCLUSION: A web-based/mobile platform for student team collaboration on therapeutic reasoning cases discussed in small group settings yielded favorable ratings, examination performance comparable to standard approaches, and was preferred by a majority of students. During the rapid shift to substantial online learning for the COVID-19 pandemic, virtual collaboration tools like PIVOT may help health professions teachers to better support groups working virtually on scaffolded therapeutic reasoning tasks.

Longitudinal Associations Between Grit, Academic Outcomes, and Residency Match Rates Among Pharmacy Students.

Objective. To characterize Grit-S scores in pharmacy students, determine whether Grit-S scores change within individual pharmacy students and cohorts over time, and investigate the relationship between Grit-S scores, academic outcomes, and professional outcomes. Methods. A survey was conducted in fall 2016 and again in fall 2017 to determine Grit-S scores in first- through fourth-year pharmacy students. Participant demographic variables, grade point average (GPA), advanced pharmacy practice experience (APPE) ratings, and residency match results were collected. Results. Over the study period, 852 survey responses were completed by 85% of students surveyed. The mean Grit-S scores of each cohort ranged from 3.5 to 3.7 (on a 5-point scale with 5 representing the highest level of grit). Underrepresented minorities had slightly higher Grit-S scores and first-generation college students had slightly lower Grit-S scores. Two hundred eighty-seven students responded to both the 2016 and 2017 surveys. Among these paired responses, small but significant changes in individual Grit-S scores over time that varied in direction and magnitude by school year were noted. Higher Grit-S scores were not associated with higher GPA or superior APPE performance, nor were they predictive of a student matching to a postgraduate pharmacy residency. Conclusion. Significant associations between grit and measures of academic or professional achievement were not detected in this pharmacy student cohort. The presence of small but significant changes in Grit-S scores over time, in the absence of any intervention, has implications that further research should be conducted in this area.

Recognizing and Overcoming Resistance to New Beta-Lactam/Beta-Lactamase Inhibitor Combinations.

PURPOSE OF REVIEW: To describe the mechanisms and clinical relevance of emergent resistance to three recently introduced beta-lactamase inhibitor combinations (BLICs) active against resistant Gram-negative organisms: ceftolozane-tazobactam, ceftazidime-avibactam, and meropenem-vaborbactam. RECENT FINDINGS: Despite their recent introduction into practice, clinical reports of resistance to BLICs among typically susceptible organisms have already emerged, in some cases associated with therapeutic failure. The resistance mechanisms vary by agent, including mutations in beta-lactamase active sites, upregulation of efflux pumps, and alterations in the structure or expression of porin channels. These changes may confer cross-resistance or, rarely, increased susceptibility to related agents. Clinicians need to be aware of the potential for initial or emergent resistance to BLICs and ensure appropriate antimicrobial susceptibility testing is performed. Dose optimization and novel combinations of agents may play a role in preventing and managing resistance. Recently approved BLICs have provided important new therapeutic options against resistant Gram-negative organisms, but are already coming up against emergent resistance. Awareness of the potential for resistance, early detection, and dose optimization may be important in preserving the utility of these agents.

A Comprehensive Survey of Infectious Diseases Curriculum Among US Pharmacy Schools.

Objective. To describe what and how infectious diseases (ID) topics are taught in US schools of pharmacy and summarize pharmacy faculty members' and students' perceived successes and challenges in teaching and learning about ID. Methods. A 23-item survey instrument was distributed electronically to ID faculty members at 137 US pharmacy schools. Data collected included curricular hours and format, topics covered, active-learning strategies, and curricular successes and concerns. Results. Surveys were collected from 106 schools (77% response rate). Infectious diseases curricula were allotted a median of 60 (IQR=40) hours of classroom time. Respondents dedicated 33% of curriculum hours to ID fundamentals and 66% to disease states. Greater than 94% of schools taught all tier one ID topics from the 2016 American College of Clinical Pharmacy Pharmacotherapy Didactic Curriculum Toolkit. Curricula were primarily delivered through traditional lectures rather than active learning (75% vs 25% of classroom time, respectively). The median number of active-learning strategies used was four (IQR=3). The most common active-learning modalities used either consistently or frequently were patient case application (98%) and audience response systems (76%). The most common successes cited by faculty members were implementation of active learning, the "real-world" applicability of the ID topics, and the breadth of topics and topic exposure covered in the curriculum. The most common concerns were a lack of time to cover material and the amount of material covered. Conclusion. Increased communication and collaboration between ID educators is warranted to increase consistency of ID education and distribution of educational innovations.

Variability in rates of use of antibacterials among 130 US hospitals and risk-adjustment models for interhospital comparison.

OBJECTIVE: To describe variability in rates of antibacterial use in a large sample of US hospitals and to create risk-adjusted models for interhospital comparison. METHODS: We retrospectively surveyed the use of 87 antibacterial agents on the basis of electronic claims data from 130 medical-surgical hospitals in the United States for the period August 2002 to July 2003; these records represented 1,798,084 adult inpatients. Hospitals were assigned randomly to the derivation data set (65 hospitals) or the validation data set (65 hospitals). Multivariable models predicting rates of antibacterial use were created using the derivation data set. These models were then used to predict rates of antibacterial use in the validation data set, which was compared with observed rates of antibacterial use. Rates of antibacterial use was measured in days of therapy per 1,000 patient-days. RESULTS: Across the surveyed hospitals, a mean of 59.3% of patients received at least 1 dose of an antimicrobial agent during hospitalization (range for individual hospitals, 44.4%-73.6%). The mean total rate of antibacterial use was 789.8 days of therapy per 1,000 patient-days (range, 454.4-1,153.4). The best model for the total rate of antibacterial use explained 31% of the variance in rates of antibacterial use and included the number of hospital beds, the number of days in the intensive care unit per 1,000 patient-days, the number of surgeries per 1,000 discharges, and the number of cases of pneumonia, bacteremia, and urinary tract infection per 1,000 discharges. Five hospitals in the validation data set were identified as having outlier rates on the basis of observed antibacterial use greater than the upper bound of the 90% prediction interval for predicted antibacterial use in that hospital. CONCLUSION: Most adult inpatients receive antimicrobial agents during their hospitalization, but there is substantial variability between hospitals in the volume of antibacterials used. Risk-adjusted models can explain a significant proportion of this variation and allow for comparisons between hospitals for benchmarking purposes.