Teams in Transition: Increasing Role of Advanced Practice Providers in Antimicrobial Use and Infectious Diseases Consultation.

Background: Advanced practice providers (APPs) have taken on increasing responsibilities as primary team members in acute care hospitals, but the impact of this practice shift on antimicrobial prescribing and infectious diseases (ID) consultation requests is unknown. Here we describe longitudinal trends in antimicrobial days of therapy (DOT) and ID consultation by attributed provider type in 3 hospitals. Methods: We performed a retrospective time series analysis of antimicrobial use and ID consultation from July 2015 to June 2022 at a major university hospital and 2 community hospitals. We evaluated antimicrobial DOT and ID consultation over time and assessed attribution to 3 groups of providers: attending physicians, trainees, and APPs. We used multinomial logistic regression to measure changes in percentage of DOT and ID consultation across the clinician groups over time using physicians as the referent. Results: Baseline distribution of antimicrobial DOT and ID consultation varied by practice setting, but all subgroups showed increases in the proportion attributable to APPs. Large increases were seen in the rate of ID consultation, increasing by >30% during the study period. At our university hospital, by study end >40% of new ID consults and restricted antimicrobial days were attributed to APPs. Conclusions: Hospitals had differing baseline patterns of DOT attributed to provider groups, but all experienced increases in DOT attributed to APPs. Similar increases were seen in changes to ID consultation. APPs have increasing involvement in antimicrobial use decisions in the inpatient setting and should be engaged in future antimicrobial stewardship initiatives.

Antimicrobial stewardship knowledge, attitudes, and practices (KAP) among nurses.

We performed a knowledge, attitudes, and practice (KAP) survey of bedside nurses to evaluate perceptions of antimicrobial use and aid in the design of nursing-based antimicrobial stewardship interventions. The survey highlighted discrepancies in knowledge and practice as well as opportunities to improve communication with nursing colleagues.

The devil's in the defaults: An interrupted time-series analysis of the impact of default duration elimination on exposure to fluoroquinolone therapy.

OBJECTIVE: To determine whether removal of default duration, embedded in electronic prescription (e-script), influenced antibiotic days of therapy. DESIGN: Interrupted time-series analysis. SETTING: The study was conducted across 2 community hospitals, 1 academic hospital, 3 emergency departments, and 86 ambulatory clinics. PATIENTS: Adults prescribed a fluoroquinolone with a duration <31 days. INTERVENTIONS: Removal of standard 10-day fluoroquinolone default duration and addition of literature-based duration guidance in the order entry on December 19, 2017. The study period included data for 12 months before and after the intervention. RESULTS: The study included 35,609 fluoroquinolone e-scripts from the preintervention period and 31,303 fluoroquinolone e-scripts from the postintervention period, accounting for 520,388 cumulative fluoroquinolone DOT. Mean durations before and after the intervention were 7.8 (SD, 4.3) and 7.7 (SD, 4.5), a nonsignificant change. E-scripts with a 10-day duration decreased prior to and after the default removal. The inpatient setting showed a significant 8% drop in 10-day e-scripts after default removal and a reduced median duration by 1 day; 10-day scripts declined nonsignificantly in ED and ambulatory settings. In the ambulatory settings, both 7- and 14-day e-script durations increased after default removal. CONCLUSION: Removal of default 10-day antibiotic durations did not affect overall mean duration but did shift patterns in prescribing, depending on practice setting. Stewardship interventions must be studied in the context of practice setting. Ambulatory stewardship efforts separate from inpatient programs are needed because interventions cannot be assumed to have similar effects.

Proposing the "Continuum of UTI" for a Nuanced Approach to Diagnosis and Management of Urinary Tract Infections.

PURPOSE: Patients with suspected UTIs are categorized into 3 clinical phenotypes based on current guidelines: no UTI, asymptomatic bacteriuria (ASB), or UTI. However, all patients may not fit neatly into these groups. Our objective was to characterize clinical presentations of patients who receive urine tests using the "continuum of UTI" approach. MATERIALS AND METHODS: This was a retrospective cohort study of a random sample of adult noncatheterized inpatient and emergency department encounters with paired urinalysis and urine cultures from 5 hospitals in 3 states between January 01, 2017, and December 31, 2019. Trained abstractors collected clinical (eg, symptom) and demographic data. A focus group discussion with multidisciplinary experts was conducted to define the continuum of UTI, a 5-level classification scheme that includes 2 new categories: lower urinary tract symptoms/other urologic symptoms and bacteriuria of unclear significance. The newly defined continuum of UTI categories were compared to the current UTI classification scheme. RESULTS: Of 220,531 encounters, 3392 randomly selected encounters were reviewed. Based on the current classification scheme, 32.1% (n = 704) had ASB and 53% (n = 1614) did not have a UTI. When applying the continuum of UTI categories, 68% of patients (n = 478) with ASB were reclassified as bacteriuria of unclear significance and 29% of patients (n = 467) with "no UTI" were reclassified to lower urinary tract symptoms/other urologic symptoms. CONCLUSIONS: Our data suggest the need to reframe our conceptual model of UTI vs ASB to reflect the full spectrum of clinical presentations, acknowledge the diagnostic uncertainty faced by frontline clinicians, and promote a nuanced approach to diagnosis and management of UTIs.

Racial disparities in Clostridioides difficile testing in three southeastern US hospitals.

OBJECTIVE: To analyze Clostridioides difficile testing in 3 hospitals in central North Carolina to validate previous racial health-disparity findings. METHODS: We completed a retrospective analysis of inpatient C. difficile tests from 2015 to 2021 at 3 university-affiliated hospitals in North Carolina. We calculated the number of C. difficile tests per 1,000 patient days stratified by race: White, Black, and non-White, non-Black (NWNB). We defined a unique C. difficile test as one that occurred in an inpatient unit with a matching laboratory accession ID and on differing calendar days. Tests were evaluated overall, by hospital, by year, and by positivity rate. RESULTS: In total, 35,160 C. difficile tests and 2,571,850 patient days across all 3 hospitals from 2015 to 2021 were analyzed. The median number of C. difficile tests per 1,000 patient days was 13.85 (interquartile range [IQR], 9.88-16.07). Among all C. difficile tests, 5,225 (15%) were positive. White patients were administered more C. difficile tests (14.46 per 1,000 patient days) than Black patients (12.96; P < .0001) or NWNB race patients (10.27; P < .0001). Black patients were administered more tests than NWNB patients (P < .0001). White patients tested positive at a similar rate to Black patients (15% vs 15%; P = .3655) and higher than NWNB individuals (12%; P = .0061), and Black patients tested positive at a higher rate than NWNB patients (P = .0024). CONCLUSION: White patients received more C. difficile tests than Black and NWNB patient groups when controlling for race patient days. Future studies should control for comorbidities and investigate community onset of C. difficile by race and ethnicity.

Using clinical decision support to improve urine testing and antibiotic utilization.

OBJECTIVE: Urine cultures collected from catheterized patients have a high likelihood of false-positive results due to colonization. We examined the impact of a clinical decision support (CDS) tool that includes catheter information on test utilization and patient-level outcomes. METHODS: This before-and-after intervention study was conducted at 3 hospitals in North Carolina. In March 2021, a CDS tool was incorporated into urine-culture order entry in the electronic health record, providing education about indications for culture and suggesting catheter removal or exchange prior to specimen collection for catheters present >7 days. We used an interrupted time-series analysis with Poisson regression to evaluate the impact of CDS implementation on utilization of urinalyses and urine cultures, antibiotic use, and other outcomes during the pre- and postintervention periods. RESULTS: The CDS tool was prompted in 38,361 instances of urine cultures ordered in all patients, including 2,133 catheterized patients during the postintervention study period. There was significant decrease in urine culture orders (1.4% decrease per month; P < .001) and antibiotic use for UTI indications (2.3% decrease per month; P = .006), but there was no significant decline in CAUTI rates in the postintervention period. Clinicians opted for urinary catheter removal in 183 (8.5%) instances. Evaluation of the safety reporting system revealed no apparent increase in safety events related to catheter removal or reinsertion. CONCLUSION: CDS tools can aid in optimizing urine culture collection practices and can serve as a reminder for removal or exchange of long-term indwelling urinary catheters at the time of urine-culture collection.

Optimizing reflex urine cultures: Using a population-specific approach to diagnostic stewardship.

BACKGROUND: Clinicians and laboratories routinely use urinalysis (UA) parameters to determine whether antimicrobial treatment and/or urine cultures are needed. Yet the performance of individual UA parameters and common thresholds for action are not well defined and may vary across different patient populations. METHODS: In this retrospective cohort study, we included all encounters with UAs ordered 24 hours prior to a urine culture between 2015 and 2020 at 3 North Carolina hospitals. We evaluated the performance of relevant UA parameters as potential outcome predictors, including sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). We also combined 18 different UA criteria and used receiver operating curves to identify the 5 best-performing models for predicting significant bacteriuria (≥100,000 colony-forming units of bacteria/mL). RESULTS: In 221,933 encounters during the 6-year study period, no single UA parameter had both high sensitivity and high specificity in predicting bacteriuria. Absence of leukocyte esterase and pyuria had a high NPV for significant bacteriuria. Combined UA parameters did not perform better than pyuria alone with regard to NPV. The high NPV ≥0.90 of pyuria was maintained among most patient subgroups except females aged ≥65 years and patients with indwelling catheters. CONCLUSION: When used as a part of a diagnostic workup, UA parameters should be leveraged for their NPV instead of sensitivity. Because many laboratories and hospitals use reflex urine culture algorithms, their workflow should include clinical decision support and or education to target symptomatic patients and focus on populations where absence of pyuria has high NPV.

Measuring empiric antibiotic spectrum-A journey through space and time.

OBJECTIVES: The typical 5-day work week affects healthcare outcomes. Structured work hours have also been implicated in antimicrobial prescribing choice. We developed a visualization tool to aid in evaluating breadth of antibiotic use in various time (day of week and hour of day) and space (patient location) combinations. METHODS: We evaluated antibiotic administration data from a tertiary-care academic medical center between July 1, 2018, and July 1, 2020. We calculated a cumulative empiric antibiotic spectrum score by adapting a previously validated antibiotic spectrum index (ASI) and applying that score to empiric antibiotic use. We visualized these data as a heat map based on various day-of-week-time combinations and then compared the distribution of scores between weekday nights, weekend days, and weekend nights to the typical workweek hours (weekday days, weekday days) using the Mann-Whitney U nonparametric test with a Bonferroni correction. RESULTS: The analysis included 76,535 antibiotic starts across 53,900 unique patient admissions over 2 years. The mean cumulative ASI was higher in all 3 night and weekend combinations (weekday nights, 7.3; weekend days, 7.6; weekend nights, 7.5) compared to the weekday daytime hours (weekday days, 7.1) and the distribution of scores was different in all groups compared to the weekday daytime reference. The cumulative ASI was also higher in intensive care units. CONCLUSIONS: Empiric antibiotic prescribing patterns differed across space and time; broader antibiotic choices occurred in the intensive care units and on nights and weekends. Visualization of these patterns aids in antimicrobial prescribing pattern recognition and may assist in finding opportunities for additional antimicrobial stewardship interventions.

Harvesting the low-hanging fruit? Comparative assessment of intravenous to oral route antimicrobial conversion policy implementation.

Policies that promote conversion of antibiotics from intravenous to oral route administration are considered "low hanging fruit" for hospital antimicrobial stewardship programs. We developed a simple metric based on digestive days of therapy divided by total days of therapy for targeted agents and a method for hospital comparisons. External comparisons may help identify opportunities for improving prospective implementation.

Asymptomatic screening for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) as an infection prevention measure in healthcare facilities: Challenges and considerations.

Testing of asymptomatic patients for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) (ie, "asymptomatic screening) to attempt to reduce the risk of nosocomial transmission has been extensive and resource intensive, and such testing is of unclear benefit when added to other layers of infection prevention mitigation controls. In addition, the logistic challenges and costs related to screening program implementation, data noting the lack of substantial aerosol generation with elective controlled intubation, extubation, and other procedures, and the adverse patient and facility consequences of asymptomatic screening call into question the utility of this infection prevention intervention. Consequently, the Society for Healthcare Epidemiology of America (SHEA) recommends against routine universal use of asymptomatic screening for SARS-CoV-2 in healthcare facilities. Specifically, preprocedure asymptomatic screening is unlikely to provide incremental benefit in preventing SARS-CoV-2 transmission in the procedural and perioperative environment when other infection prevention strategies are in place, and it should not be considered a requirement for all patients. Admission screening may be beneficial during times of increased virus transmission in some settings where other layers of controls are limited (eg, behavioral health, congregate care, or shared patient rooms), but widespread routine use of admission asymptomatic screening is not recommended over strengthening other infection prevention controls. In this commentary, we outline the challenges surrounding the use of asymptomatic screening, including logistics and costs of implementing a screening program, and adverse patient and facility consequences. We review data pertaining to the lack of substantial aerosol generation during elective controlled intubation, extubation, and other procedures, and we provide guidance for when asymptomatic screening for SARS-CoV-2 may be considered in a limited scope.

Evaluation of hospital blood culture utilization rates to identify opportunities for diagnostic stewardship.

OBJECTIVES: To evaluate the pattern of blood-culture utilization among a cohort of 6 hospitals to identify potential opportunities for diagnostic stewardship. METHODS: We completed a retrospective analysis of blood-culture utilization during adult inpatient or emergency department (ED) encounters in 6 hospitals from May 2019 to April 2020. We investigated 2 measures of blood-culture utilization rates (BCURs): the total number of blood cultures, defined as a unique accession number per 1,000 patient days (BCX) and a new metric of blood-culture events per 1,000 patient days to account for paired culture practices. We defined a blood-culture event as an initial blood culture and all subsequent samples for culture drawn within 12 hours for patients with an inpatient or ED encounter. Cultures were evaluated by unit type, positivity and contamination rates, and other markers evaluating the quality of blood-culture collection. RESULTS: In total, 111,520 blood cultures, 52,550 blood culture events, 165,456 inpatient admissions, and 568,928 patient days were analyzed. Overall, the mean BCUR was 196 blood cultures per 1,000 patient days, with 92 blood culture events per 1,000 patient days (range, 64-155 among hospitals). Furthermore, 7% of blood-culture events were single culture events, 55% began in the ED, and 77% occurred in the first 3 hospital days. Among all blood cultures, 7.7% grew a likely pathogen, 2.1% were contaminated, and 5.9% of first blood cultures were collected after the initiation of antibiotics. CONCLUSIONS: Blood-culture utilization varied by hospital and was heavily influenced by ED culture volumes. Hospital comparisons of blood-culture metrics can assist in identifying opportunities to optimize blood-culture collection practices.

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.

Use of Contact Networks to Estimate Potential Pathogen Risk Exposure in Hospitals.

Importance: Person-to-person contact is important for the transmission of health care-associated pathogens. Quantifying these contact patterns is crucial for modeling disease transmission and understanding routes of potential transmission. Objective: To generate and analyze the mixing matrices of hospital patients based on their contacts within hospital units. Design, Setting, and Participants: In this quality improvement study, mixing matrices were created using a weighted contact network of connected hospital patients, in which contact was defined as occupying the same hospital unit for 1 day. Participants included hospitalized patients at 299 hospital units in 24 hospitals in the Southeastern United States that were part of the Duke Antimicrobial Stewardship Outreach Network between January 2015 and December 2017. Analysis was conducted between October 2021 and February 2022. Main Outcomes and Measures: The mixing matrices of patients for each hospital unit were assessed using age, Elixhauser Score, and a measure of antibiotic exposure. Results: Among 1 549 413 hospitalized patients (median [IQR] age, 44 [26-63] years; 883 580 [56.3%] women) in 299 hospital units, some units had highly similar patterns across multiple hospitals, although the number of patients varied to a great extent. For most of the adult inpatient units, frequent mixing was observed for older adult groups, while outpatient units (eg, emergency departments and behavioral health units) showed mixing between different age groups. Most units mixing patterns followed the marginal distribution of age; however, patients aged 90 years or older with longer lengths of stay created a secondary peak in some medical wards. From the mixing matrices by Elixhauser Score, mixing between patients with relatively higher comorbidity index was observed in intensive care units. Mixing matrices by antibiotic spectrum, a 4-point scale based on priority for antibiotic stewardship programs, resulted in 6 major distinct patterns owing to the variation of the type of antibiotics used in different units, namely those dominated by a single antibiotic spectrum (narrow, broad, or extended), 1 pattern spanning all antibiotic spectrum types and 2 forms of narrow- and extended-spectrum dominant exposure patterns (an emergency room where patients were exposed to one type of antibiotic or the other and a pediatric ward where patients were exposed to both types). Conclusions and Relevance: This quality improvement study found that the mixing patterns of patients both within and between hospitals followed broadly expected patterns, although with a considerable amount of heterogeneity. These patterns could be used to inform mathematical models of health care-associated infections, assess the appropriateness of both models and policies for smaller community hospitals, and provide baseline information for the design of interventions that rely on altering patient contact patterns, such as practices for transferring patients within hospitals.

Impact of Education and Data Feedback on Guideline-Concordant Prescribing for Urinary Tract Infections in the Outpatient Setting.

BACKGROUND: Urinary tract infections (UTIs) are the most common outpatient indication for antibiotics and an important target for antimicrobial stewardship (AS) activities. With The Joint Commission standards now requiring outpatient AS, data supporting effective strategies are needed. METHODS: We conducted a 2-phase, prospective, quasi-experimental study to estimate the effect of an outpatient AS intervention on guideline-concordant antibiotic prescribing in a primary care (PC) clinic and an urgent care (UC) clinic between August 2017 and July 2019. Phase 1 of the intervention included the development of clinic-specific antibiograms and UTI diagnosis and treatment guidelines, presented during educational sessions with clinic providers. Phase 2, consisting of routine clinic- and provider-specific feedback, began ~12 months after the initial education. The primary outcome was percentage of encounters with first- or second-line antibiotics prescribed according to clinic-specific guidelines and was assessed using an interrupted time series approach. RESULTS: Data were collected on 4724 distinct patients seen during 6318 UTI encounters. The percentage of guideline-concordant prescribing increased by 22% (95% CI, 12% to 32%) after Phase 1 education, but decreased by 0.5% every 2 weeks afterwards (95% CI, -0.9% to 0%). Following routine data feedback in Phase 2, guideline concordance stabilized, and significant further decline was not seen (-0.6%; 95% CI, -1.6% to 0.4%). This shift in prescribing patterns resulted in a 52% decrease in fluoroquinolone use. CONCLUSIONS: Clinicians increased guideline-concordant prescribing, reduced UTI diagnoses, and limited use of high-collateral damage agents following this outpatient AS intervention. Routine data feedback was effective to maintain the response to the initial education.

Impact of Education and Data Feedback on Antibiotic Prescribing for Urinary Tract Infections in the Emergency Department: An Interrupted Time-Series Analysis.

BACKGROUND: Urinary tract infections (UTIs) are often misdiagnosed or treated with exceedingly broad-spectrum antibiotics, leading to negative downstream effects. We aimed to implement antimicrobial stewardship (AS) strategies targeting UTI prescribing in the emergency department (ED). METHODS: We conducted a quasi-experimental prospective AS intervention outlining appropriate UTI diagnosis and management across 3 EDs, within an academic and 2 community hospitals, in North Carolina, United States. The study was divided into 3 phases: a baseline period and 2 intervention phases. Phase 1 included introduction of an ED-specific urine antibiogram and UTI guideline, education, and department-specific feedback on UTI diagnosis and antibiotic prescribing. Phase 2 included re-education and provider-specific feedback. Eligible patients included adults with an antibiotic prescription for UTI diagnosed in the ED from 13 November 2018 to 1 March 2021. Admitted patients were excluded. The primary outcome was guideline-concordant antibiotic use, assessed using an interrupted time-series regression analysis with 2-week intervals. RESULTS: Overall, 8742 distinct patients with 10 426 patient encounters were included. Ninety-two percent of all encounters (n = 9583) were diagnosed with cystitis and 8.1% with pyelonephritis (n = 843). There was an initial 15% increase in guideline-concordant antibiotic prescribing in phase 1 compared with the preintervention period (incidence rate ratio [IRR], 1.15; 95% confidence interval [CI], 1.03-1.29). A significant increase in guideline-concordant prescriptions was seen with every 2-week interval during phase 2 (IRR, 1.03; 95% CI, 1.01-1.04). CONCLUSIONS: This multifaceted AS intervention involving a guideline, education, and provider-specific feedback increased guideline-concordant antibiotic choices for treat-and-release patients in the ED.

Impact of Antibiotic Stewardship Rounds in the Intensive Care Setting: A Prospective Cluster-Randomized Crossover Study.

BACKGROUND: Few groups have formally studied the effect of dedicated antibiotic stewardship rounds (ASRs) on antibiotic use (AU) in intensive care units (ICUs). METHODS: We implemented weekly ASRs using a 2-arm, cluster-randomized, crossover study in 5 ICUs at Duke University Hospital from November 2017 to June 2018. We excluded patients without an active antibiotic order, or if they had a marker of high complexity including an existing infectious disease consult, transplantation, ventricular assist device, or extracorporeal membrane oxygenation. AU during and following ICU stay for patients with ASRs was compared to the controls. We recorded the number of reviews, recommendations delivered, and responses. We evaluated change in ICU-specific AU during and after the study. RESULTS: Our analysis included 4683 patients: 2330 intervention and 2353 controls. Teams performed 761 reviews during ASRs, which excluded 1569 patients: 60% of patients off antibiotics, and 8% complex patients. Exclusions affected 88% of cardiothoracic ICU (CTICU) patients. The AU rate ratio (RR) was 0.97 (95% confidence interval [CI], .91-1.04). When CTICU was removed, the RR was 0.93 (95% CI, .89-.98). AU in the poststudy period decreased by 16% (95% CI, 11%-24%) compared to AU in the baseline period. Change in AU was differential among units: largest in the neurology ICU (-28%) and smallest in the CTICU (-2%). CONCLUSIONS: Weekly multidisciplinary ASRs was a high-resource intervention associated with a small AU reduction. The noticeable ICU AU decline over time is possibly due to indirect effects of ASRs. Effects differed among specialty ICUs, emphasizing the importance of customizing ASRs to match unit-specific population, workflow, and culture.

The impact of patient-reported penicillin or cephalosporin allergy on surgical site infections.

OBJECTIVE: To determine the impact of a documented penicillin or cephalosporin allergy on the development of surgical site infections (SSIs). BACKGROUND: Appropriate preoperative antibiotic prophylaxis reduces SSI risk, but documented antibiotic allergies influence the choice of prophylactic agents. Few studies have examined the relationship between a reported antibiotic allergy and risk of SSI and to what extent this relationship is modified by the antibiotic class given for prophylaxis. METHODS: We conducted a retrospective cohort study of adult patients undergoing coronary artery bypass, craniotomy, spinal fusion, laminectomy, hip arthroplasty and knee arthroplasty at 3 hospitals from July 1, 2013, to December 31, 2017. We built a multivariable logistic regression model to calculate the adjusted odds ratio (aOR) of developing an SSI among patients with and without patient-reported penicillin or cephalosporin allergies. We also examined effect measure modification (EMM) to determine whether surgical prophylaxis affected the association between reported allergy and SSI. RESULTS: We analyzed 39,972 procedures; 1,689 (4.2%) with a documented patient penicillin or cephalosporin allergy, and 374 (0.9%) resulted in an SSI. Patients with a reported penicillin or cephalosporin allergy were more likely to develop an SSI compared to patients who did not report an allergy to penicillin or cephalosporins (adjusted odds ratio, 3.26; 95% confidence interval, 2.71-3.93). Surgical prophylaxis did not have significant EMM on this association. CONCLUSIONS: Patients who reported a penicillin or cephalosporin allergy had higher odds of developing an SSI than nonallergic patients. However, the increase in odds is not completely mediated by the type of surgical prophylaxis. Instead, a reported allergy may be a surrogate marker for a more complicated patient population.

Challenges in hospital-acquired coronavirus disease 2019 (COVID-19) surveillance and attribution of infection source.

We performed surveillance for hospital-acquired COVID-19 (HA-COVID-19) and compared time-based, electronic definitions to real-time adjudication of the most likely source of acquisition. Without real-time adjudication, nearly 50% of HA-COVID-19 cases identified using electronic definitions were misclassified. Both electronic and traditional contact tracing methods likely underestimated the incidence of HA-COVID-19.