The Impact of Reported Beta-Lactam Allergy in Hospitalized Patients With Hematologic Malignancies Requiring Antibiotics

Impact of Sulfonamide Allergy Label on Clinical Outcomes in Patients with Pneumocystis jirovecii Pneumonia

INTRODUCTION

The presence of antibiotic allergy labels can have harmful impacts on clinical outcomes, particularly among immunosuppressed patients, in whom there have been associations with increased complications, readmission rates, and mortality. We explore the effects of a sulfonamide allergy label (SAL) on clinical outcomes in adult patients with Pneumocystis jirovecii pneumonia (PJP).

METHODS

In this retrospective matched cohort study, we utilized TriNetX, a multicenter national database, to match 535 adult patients with PJP and SAL to an equal number of controls. We identified cases indexed between 01/01/2010 and 01/01/2023 utilizing ICD-10 codes for PJP and allergy status to sulfonamides and through detection of P. jirovecii antigen with immunofluorescence or PCR. Propensity score matching was performed in a 1:1 fashion for demographics and comorbidities, and our analysis included clinical outcomes that occurred within 30 days after the occurrence of the index event.

RESULTS

While hospitalization risk tended to be lower among patients with SAL as compared to controls (RR: 0.90; 95% CI 0.81-1.01), there were no major differences in the risk of respiratory failure (RR: 0.94; 95% CI 0.84-1.05), prednisone use (RR: 1; 95% CI 0.91-1.10), intensive level of care requirement (RR: 0.85; 95% CI 0.69-1.06), intubation (RR: 0.85; 95% CI 0.61-1.19), or mortality (RR: 0.98; 95% CI 0.68-1.42). The presence of SAL did however impact antibiotic prescription patterns, with an underutilization of trimethoprim (RR: 0.50; 95% CI 0.43-0.59) and sulfamethoxazole (RR, 0.47; 95% CI 0.40-0.56) and overuse of alternative agents by patients with SAL as compared to controls. Yet, there was no difference in the occurrence of adverse outcomes such as hepatotoxicity (RR: 1.09; 95% CI 0.49-2.45) or acute kidney injury (RR: 0.94; 95% CI 0.78-1.14) between patients with SAL and controls.

CONCLUSIONS

The presence of SAL alters antibiotic prescription patterns among adults with Pneumocystis infection but has no clinically significant impact on outcomes.

Delabeling of allergy to beta-lactam antibiotics in hospitalized patients: a prospective study evaluating cost savings

BACKGROUND

Patients with a penicillin allergy label are at risk of an associated increase in adverse antibiotic events and hospitalization costs.

AIM

We aimed to study the economic savings derived from the correct diagnosis and delabeling inpatients with suspected beta-lactam allergy, considering the acquisition cost of antimicrobials prescribed during a patient's hospital stay.

METHOD

We prospectively evaluated patients admitted to the University Hospital of Salamanca who had been labeled as allergic to beta-lactams and performed a delabeling study. Subsequently, cost differences between antibiotics administered before and after the allergy study and those derived from those patients who received alternative antibiotics during admission and those who switched to beta-lactams after the allergy study were calculated.

RESULTS

One hundred seventy-seven inpatients labeled as allergic to beta-lactams underwent a delabeling study; 34 (19.2%) were confirmed to have allergy to beta-lactams. Of the total number of patients, 136 (76.8%) received antibiotics during their hospitalization, involving a mean (SD) cost of €203.07 (318.42) and a median (IQR) cost of €88.97 (48.86-233.56). After delabeling in 85 (62.5%) patients, the antibiotic treatment was changed to beta-lactams. In this group of patients, the mean cost (SD) decreased from €188.91 (351.09) before the change to 91.31 (136.07) afterward, and the median cost (IQR) decreased from €72.92 (45.82-211.99) to €19.24 (11.66-168). The reduction was significant compared to the median cost of patients whose treatment was not changed to beta-lactams (p<0.001).

CONCLUSION

Delabeling hospitalized patients represents a cost-saving measure for treating patients labeled as allergic to beta-lactams.

Antimicrobial use and appropriateness in neutropenic fever: a study of the Hospital National Antimicrobial Prescribing Survey data

BACKGROUND

Neutropenic fever (NF) is a common complication in patients receiving chemotherapy. Judicious antimicrobial use is paramount to minimize morbidity and mortality and to avoid antimicrobial-related harms.

OBJECTIVES

To use an Australian national dataset of antimicrobial prescriptions for the treatment of NF to describe antimicrobial use, prescription guideline compliance and appropriateness; and to compare these findings across different healthcare settings and patient demographics. We also aimed to identify trends and practice changes over time.

METHODS

Data were extracted from the Hospital National Antimicrobial Prescribing Survey (Hospital NAPS) database from August 2013 to May 2022. Antimicrobial prescriptions with a NF indication were analysed for antimicrobial use, guideline compliance and appropriateness according to the Hospital NAPS methodology. Demographic factors, hospital classifications and disease characteristics were compared.

RESULTS

A total of 2887 (n = 2441 adults, n = 441 paediatric) NF prescriptions from 254 health facilities were included. Piperacillin-tazobactam was the most prescribed antimicrobial. Overall, 87.4% of prescriptions were appropriate. Piperacillin-tazobactam and cefepime had the highest appropriateness though incorrect piperacillin-tazobactam dosing was observed. Lower appropriateness was identified for meropenem, vancomycin, and gentamicin prescribing particularly in the private hospital and paediatric cohorts. The most common reasons for inappropriate prescribing were spectrum too broad, incorrect dosing or frequency, and incorrect duration.

CONCLUSIONS

This study provides insights into antimicrobial prescribing practices for NF in Australia. We have identified three key areas for improvement: piperacillin-tazobactam dosing, paediatric NF prescribing and private hospital NF prescribing. Findings from this study will inform the updated Australian and New Zealand consensus guidelines for the management of neutropenic fever in patients with cancer.

Antimicrobial Stewardship in Immunocompromised Patients: Current State and Future Opportunities

Immunocompromised (IC) patients are high risk for complications due to a high rate of antibiotic exposure. Antimicrobial stewardship interventions targeted to IC patients can be challenging due to limited data in this population and a high risk of severe infection-related outcomes. Here, the authors review immunocompromised antimicrobial stewardship barriers, metrics, and opportunities for antimicrobial use and testing optimization. Last, the authors highlight future steps in the field.

A retrospective case-control study to evaluate the use of beta-lactam desensitization in the management of penicillin-allergic patients: a potential strategy for Antimicrobial Stewardship Programs

Introduction: Penicillin allergy labels (PAL) are common in the hospital setting and are associated with worse clinical outcomes. Desensitization can be a useful strategy for allergic patients when alternative options are suboptimal or not available. The aim was to compare clinical outcomes of patients with PAL managed with antibiotic desensitization vs. those who received alternative non-beta-lactam antibiotic treatments. Methods: A retrospective 3:1 case-control study was performed between 2015-2022. Cases were adult PAL patients with infection who required antibiotic desensitization; controls were PAL patients with infection managed with an alternative antibiotic treatment. Cases and controls were adjusted for age, sex, infection source, and critical or non-critical medical services. Results: Fifty-six patients were included: 14 in the desensitization group, 42 in the control group. Compared to the control group, desensitized PAL patients had more comorbidities, with a higher Charlson index (7.4 vs. 5; p = 0.00) and more infections caused by multidrug-resistant (MDR) pathogens (57.1% vs. 28.6%; p = 0.05). Thirty-day mortality was 14.3% in the desensitized group, 28.6% in the control group (p = 0.24). Clinical cure occurred in 71.4% cases and 54.8% controls (p = 0.22). Four control patients selected for MDR strains after alternative treatment; selection of MDR strains did not occur in desensitized patients. Five controls had antibiotic-related adverse events, including Clostridioides difficile or nephrotoxicity. No antibiotic-related adverse events were found in the study group. In multivariate analysis, no differences between groups were observed for main variables. Conclusion: Desensitization was not associated with worse clinical outcomes, despite more severe patients in this group. Our study suggests that antibiotic desensitization may be a useful Antimicrobial Stewardship tool for the management of selected PAL patients.

Approach for delabeling beta-lactam allergy in children

A considerable number of pediatric patients treated with beta-lactam (BL) antibiotics develop delayed onset of skin rashes during the course of treatment. Although the most frequent cause of these symptoms is infectious, many cases are labeled as allergic reactions to these drugs. BL allergy labels could have a negative impact, as they imply avoidance of this group of drugs and the use of second-line antibiotics, leading to a potential increase in adverse effects and the utilization of less effective therapies. This constitutes a major public health concern and economic burden, as the use of broad-spectrum antibiotics can result in multidrug-resistant organisms and prolonged hospital stays. Therefore, it is crucial to delabel patients during childhood to avoid false labeling in adult life. Although the label of BL allergy is among the most frequent causes of allergy referral, its management remains controversial, and new diagnostic perspectives are changing the paradigm of managing BL allergies in children. Traditionally, drug provocation testing (DPT) was exclusively performed in patients who had previously obtained negative results from skin tests (STs). However, the sensitivity of STs is low, and the role of in vitro testing in the pediatric population is not well defined. Recent studies have demonstrated the safety of direct DPT without prior ST or serum tests for pediatric patients who report a low-risk reaction to BLs, which is cost-effective. However, there is still a debate on the optimal allergic workup to be performed in children with a benign immediate reaction and the management of children with severe cutaneous adverse drug reactions. In this review, we will discuss the impact of the label of BL allergy and the role of the different tools currently available to efficiently address BL allergy delabeling in children.

A new clinical opportunity: Rechallenging penicillin allergy in an outpatient pharmacy

In the United States, approximately 27 million people have a documented penicillin allergy, but 90% of the allergies are falsely labeled. By rechallenging suspected allergies, a pharmacist can optimize patient care, fulfill antimicrobial stewardship objectives, and educate patients on true allergies. We suggest a protocol that allows pharmacists to investigate the presence of an allergy and conduct a challenge when indicated. The protocol consists of a patient interview, a risk assessment, an oral rechallenge, and the potential for a skin test. The testing and delabeling of penicillin allergies will enhance the practice of antimicrobial stewardship in the outpatient setting. In the changing landscape of pharmacy, community pharmacists can increase their services and improve patient care. Owing to limited documented experience in the outpatient pharmacy, an opportunity to set the standard and be a leader in the field is present.

Does thePenicillin Allergy Label Affect Outcomes of Complicated Odontogenic Infections?

PURPOSE

Penicillins are a potent antibiotic in managing odontogenic infections, but 10% of the population is labelled as allergic to these drugs. This has limited their use and resulted in increased utilization of health care resources as well as complications associated with alternative antibiotics. The purpose of the study was to measure the association between patients labeled as penicillin allergic and treatment outcomes in a sample of patients treated for complicated odontogenic infections. Additionally, we sought to investigate antibiotic resistance patterns in these patients.

MATERIALS AND METHODS

A retrospective cohort study was performed at the Michigan Medicine health care system to include patients who were treated for complicated odontogenic infections by oral and maxillofacial surgery between 2016 and 2020. Complicated odontogenic infection was defined as any odontogenic infection requiring admission and surgical management in the operating room. The primary predictor variable was the penicillin allergy label, which was determined by chart review and not confirmed with formal testing. Outcomes were measures of disease severity. The primary outcome variable was hospital length of stay. Secondary outcome variables were ICU admission (yes/no), repeat computed tomography scan(s), repeat surgery (yes/no), and re-admission (yes/no). Co-variates included were age, sex (male/female), tobacco use status, diabetes, immunocompromised state, number of spaces involved, white blood cell count upon admission and insurance status. For our secondary aim, the primary predictor variable was again penicillin allergy and outcome variable was antibiotic resistance as determined by wound culture results following surgical intervention. Negative binomial regression and logistic regression analyses were performed. P < .05 was considered significant.

RESULTS

A total of 150 patients met the inclusion criteria and of those 17.3% reported as penicillin allergic. Patients labelled as penicillin allergic did not differ significantly from patients without penicillin allergy label in terms of treatment outcomes. Age, diabetes, and immunosuppression were associated with an increased length of stay. Patients labelled as penicillin allergic were at significantly higher risk for antibiotic resistance (relative risk = 2.34; 95% confidence interval, 1.66 to 3.32; P < .001), specifically clindamycin resistance (relative risk = 3.17; 95% confidence interval, 1.93 to 5.18; P < .001).

CONCLUSIONS

Penicillin allergy was significantly associated with clindamycin resistance. There were similar outcomes amongst patients with and without a penicillin allergy label despite antibiotic differences. Delabeling efforts for patients with a reported penicillin allergy must be considered and local nomograms for antibiotic selection should be used by providers when seeking alternative antibiotics.

The Burden of Self-Reported Antibiotic Allergies in Health Care and How to Address It: A Systematic Review of the Evidence

BACKGROUND

Antibiotics are the first-line treatment for bacterial infections; however, overuse and inappropriate prescribing have made antibiotics less effective with increased antimicrobial resistance. Unconfirmed reported antibiotic allergy labels create a significant barrier to optimal antimicrobial stewardship in health care, with clinical and economic implications.

OBJECTIVE

A systematic review was conducted to summarize the impact of patient-reported antibiotic allergy on clinical outcomes and various strategies that have been employed to effectively assess and remove these allergy labels, improving patient care.

METHODS

The review was undertaken using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A critical appraisal was conducted on all studies and a narrative synthesis was performed to identify themes.

RESULTS

Four themes emerged: the prevalence of antibiotic allergy, impact of antibiotic allergy on antimicrobial prescribing, impact of antibiotic allergy on clinical outcomes, and delabeling strategies to improve clinical outcomes. Of the 32 studies, including 1,089,675 participants, the prevalence of reported antibiotic allergy was between 5% and 35%. Patients with a reported antibiotic allergy had poorer concordance with prescribing guidelines in 30% to 60% of cases, with a higher use of alternatives such as quinolone, tetracycline, macrolide, lincosamide, and carbapenem and lower use of beta-lactam antibiotics. Antibiotic allergy delabeling was identified as an intervention and recommendation to advance the state of the science.

CONCLUSIONS

There is substantial evidence within the literature that antibiotic allergy labels significantly impact patient clinical outcomes and a consensus that systematic assessment of reported antibiotic allergies, commonly referred to as delabeling, improves the clinical management of patients.

Advances in antibacterial treatment of adults with high-risk febrile neutropenia

BACKGROUND

High-risk febrile neutropenia (HR-FN) is a life-threatening complication in patients with haematological malignancies or receiving myelosuppressive chemotherapy. Since the last international guidelines were published over 10 years ago, there have been major advances in the understanding and management of HR-FN, including on antibiotic pharmacokinetics and discontinuation/de-escalation strategies.

OBJECTIVES

Summarizing major advances in the field of antibacterial therapy in patients with HR-FN: empirical therapy, pharmacokinetics of antibiotics and antibiotic stewardship.

SOURCES

Narrative review based on literature review from PubMed. We focused on studies published between 2010 and 2023 about the pharmacokinetics of antimicrobials, management of antimicrobial administration, and discontinuation/de-escalation strategies. We did not address antimicrobial prophylaxis, viral or fungal infections.

CONTENT

Several high-quality publications have highlighted important modifications of antibiotic pharmacokinetics in HR-FN, with standard dosages exposing patients to underdosing. These recent clinical and population pharmacokinetics studies help improve management protocols with optimized initial dosing and infusion rules for β-lactams, vancomycin, daptomycin and amikacin; they highlight the potential benefits of therapeutic drug monitoring. A growing body of evidence also shows that antibiotic discontinuation/de-escalation strategies are beneficial for bacterial ecology and patients' outcome. We further discuss methods and limitations for implementation of such protocols in haematology.

IMPLICATIONS

We highlight recent information about the management of antibacterial therapy in HR-FN that might be considered in updated guidelines for HR-FN management.

Characterizing Antibiotic Allergy Labels in a Large UK Hospital Population to Inform Antimicrobial Stewardship and Delabeling Assessment Strategy

BACKGROUND

Antibiotic allergy labels are important barriers to treatment and antimicrobial stewardship, but their prevalence in UK hospitals is poorly described.

OBJECTIVE

To ascertain the prevalence and characteristics of antibiotic allergy labels in a large UK hospital setting and estimate the proportion of penicillin allergy labels for which point-of-care (POC) delabeling assessment would be appropriate.

METHODS

Electronic health records data were analyzed from all patients treated at Cambridge University Hospitals NHS Foundation Trust in 2019. Validated POC delabeling risk stratification criteria were retrospectively applied to penicillin allergy labels.

RESULTS

Recorded reactions to antibiotics were present in 11.8% of all patients (32,148 of 273,216), 16.3% of inpatients (13,874 of 85,230), and 9.7% of outpatients (18,274 of 187,986). Penicillins were the commonest reaction precipitant described (9.0% of patients; 24,646 of 273,216), followed by sulfonamides/trimethoprim (1.4%; 3869 of 273,216) and macrolides/lincosamides (1.3%; 3644 of 273,216). A total of 3.9% of inpatients had recorded reactions to >1 antibiotic class (3348 of 85,230). Cutaneous manifestations were the most commonly described reaction features (40.7% of labels; 15,821 of 38,902). Of 15,949 labels describing probable or possible penicillin "allergy" with sufficient detail to allow for the retrospective assessment of POC delabeling suitability, 1702 were deemed suitable for removal or downgrading of the label to "intolerance" without further investigation (10.7%), 11,887 were appropriate for POC assessment using an oral penicillin challenge (OPC) or OPC with prior bedside skin testing (74.5%), and 2360 were identified as unsuitable for any form of POC assessment (14.8%).

CONCLUSIONS

Antibiotic allergy labels are highly prevalent in a UK hospital setting. A large proportion of penicillin allergy labels may be suitable for POC delabeling assessment.

Penicillin allergy evaluation in hospitalized patients with hematologic malignancy

A penicillin allergy testing service (PATS) assessed penicillin allergy in patients with hematologic malignancies; 17 patients who met criteria had negative skin testing. Patients who underwent penicillin challenge passed and were delabeled. Of delabeled patients, 87% received and tolerated β-lactams during follow-up. Providers found the PATS valuable.

Penicillin allergy delabeling: Opportunities for implementation and dissemination

Although existing as a safety measure to prevent iatrogenic harm, unconfirmed penicillin allergy labels have a negative impact on personal and public health. One downstream effect of unconfirmed penicillin allergy is the continued emergence and transmission of resistant bacteria and their associated health care costs. Recognizing the consequences of inaccurate penicillin allergy labels, professional and public health organizations have started promoting the adoption of proactive penicillin allergy evaluations, with the ultimate goal of removing the penicillin allergy label when the allergy is disproved, also known as penicillin allergy "delabeling." A penicillin allergy evaluation includes a comprehensive allergy history often followed by drug challenge, sometimes with preceding skin testing. Currently, penicillin allergy delabeling is largely carried out by allergy specialists in outpatient settings. Penicillin allergy delabeling is performed on inpatients, albeit rarely, often at the time of need, as a point-of-care procedure. Access to penicillin allergy evaluation services is limited. Recent studies demonstrate the feasibility of expanding penicillin allergy evaluations and delabeling to internists, pediatricians, emergency medicine physicians, infectious diseases specialists, and clinical pharmacists. However, reducing the impact of mislabeled penicillin allergy will require comprehensive efforts and new investments. In this review, we summarize the current practices of penicillin allergy delabeling and discuss expansion opportunities for penicillin allergy delabeling as quality improvement.

[Efficiency of the allergological study in the diagnosis of allergic reactions to beta-lactams]

AIMS

Assessing the rate of β-lactams-allergic patients who are still labelled as such in their medical records after being performed an allergic test; as well as the rate of no allergic patients who were prescribed one of these antibiotics; and pondering whether the allergic test is hence cost-effective.

METHODS

This is a retrospective study developed from 2019 to 2021 focusing on patients suspected of β-lactams allergy (n=688). By means of an allergy test, it was cleared out if they were actually allergic. Later, we checked if the patient was still labelled as allergic in their medical record. Tracking through the digital health services card, we followed up if the antibiotic was ever prescribed again, and if the drug was then dispensed to the patient.

RESULTS

11.3% of the patients showed hypersensitivity to β-lactams. Nonetheless, 33.1% of the patients were still considered allergic to these antibiotics in their medical record even though not being such. 32% of the patients - who had their allergy confirmed - had been labelled without the general practitioner's acknowledgment, and 32.8% had even been prescribed a β-lactam again.

CONCLUSIONS

Discarding any allergy to β-lactams is as important as registering the allergy on medical records after testing the patient. A remarkable quantity of non-allergic patients is still addressed as actual allergic, in spite not being such. Labelling patients as β-lactams allergic may have consequences, short-term and long-term, for the patient but also for the health service budget.

The association between penicillin allergy and surgical site infection after orthopedic surgeries: a retrospective cohort study

Background

Cephalosporins are used as first-line antimicrobial prophylaxis for orthopedics surgeries. However, alternative antibiotics are usually used in the presence of penicillin allergy (PA), which might increase the risk of surgical site infection (SSI). This study aimed to analyze the relationship between SSI after orthopedic surgeries and PA among surgical candidates and related alternative antibiotic use.

Methods

In this single-center retrospective cohort study, we compared inpatients with and without PA from January 2015 to December 2021. The primary outcome was SSI, and the secondary outcomes were SSI sites and perioperative antibiotic use. Moreover, pathogen characteristics of all SSIs were also compared between the two cohorts.

Results

Among the 20,022 inpatient records, 1704 (8.51%) were identified with PA, and a total of 111 (0.55%) SSI incidents were reported. Compared to patients without PA, patients with PA had higher postoperative SSI risk (1.06%, 18/1704 vs. 0.51%, 93/18318), shown both in multivariable regression analysis (odds ratio [OR] 2.11; 95% confidence interval [CI], 1.26-3.50; p= 0.004) and propensity score matching (OR 1.84; 95% CI, 1.05-3.23; p= 0.034). PA was related to elevated deep SSI risk (OR 2.79; 95% CI, 1.47-5.30; p= 0.002) and had no significant impact on superficial SSI (OR 1.39; 95% CI, 0.59-3.29; p= 0.449). The PA group used significantly more alternative antibiotics. Complete mediation effect of alternative antibiotics on SSI among these patients was found in mediation analysis. Pathogen analysis revealed gram-positive cocci as the most common pathogen for SSI in our study cohort, while patients with PA had higher infection rate from gram-positive rods and gram-negative rods than non-PA group.

Conclusion

Compared to patients without PA, patients with PA developed more SSI after orthopedic surgeries, especially deep SSI. The elevated infection rate could be secondary to the use of alternative prophylactic antibiotics.

Penicillin Allergy Label Is Associated With Worse Clinical Outcomes in Bacterial Pneumonia

BACKGROUND

Penicillins (PCNs) are a first-line treatment option for bacterial pneumonia. PCN allergy label can delay antimicrobial treatment and result in the use of alternative antibiotic regimens risking an inadequate response to treatment and potentially increased adverse drug reactions.

OBJECTIVE

To investigate the impact of PCN allergy label on clinical outcomes of bacterial pneumonia.

METHODS

This retrospective cohort study used TriNetX, a web-based tool for population cohort research, to identify adult patients with and without PCN allergy label diagnosed with bacterial pneumonia. Cohorts were matched for baseline demographics and chronic medical conditions. The 30-day risks of hospitalization, acute respiratory failure, intubation, need for intensive level of care, and mortality were compared. Antibiotics used and their possible adverse reactions were explored.

RESULTS

After matching, there were 68,748 patients in each cohort. Patients with bacterial pneumonia with PCN allergy label had higher risks of hospitalization (risk ratio [RR], 1.23; 95% confidence interval [CI], 1.22-1.24), acute respiratory failure (RR, 1.14; 95% CI, 1.12-1.15), intubation (RR, 1.18; 95% CI, 1.13-1.22), intensive level of care (RR, 1.11; 95% CI, 1.08-1.14), and mortality (RR, 1.08; 95% CI, 1.04-1.13) compared with patients without PCN allergy label. Patients with PCN allergy label had decreased use of PCNs and cephalosporins and increased utilization of other antibiotic classes compared with patients without PCN allergy label. PCN allergy label was also associated with increased risk of adverse drug reactions.

CONCLUSION

PCN allergy label is associated with worse clinical outcomes in bacterial pneumonia, and risk mitigation strategies should be considered.

Use of a penicillin allergy clinical decision rule to enable direct oral penicillin provocation: an international multicentre randomised control trial in an adult population (PALACE): study protocol

INTRODUCTION

Penicillin allergies are highly prevalent in the healthcare setting and associated with the prescription of second-line inferior antibiotics. More than 85% of all penicillin allergy labels can be removed by skin testing and 96%-99% of low-risk penicillin allergy labels can be removed by direct oral challenge. An internally and externally validated clinical assessment tool for penicillin allergy, PEN-FAST, can identify a low-risk penicillin allergy without the need for skin testing; a score of less than 3 has a negative predictive value of 96.3% (95% CI, 94.1 to 97.8) for the presence of a penicillin allergy. It is hypothesised that PEN-FAST is a safe and effective tool for assessing penicillin allergy in an outpatient clinic setting.

METHODS AND ANALYSIS

This is an international, multicentre randomised control trial using the PEN-FAST tool to risk-stratify penicillin allergy labels in adult outpatients. The study's primary objective is to evaluate the non-inferiority of using PEN-FAST score-guided management with direct oral challenge compared with standard care (defined as prick and intradermal skin testing followed by oral penicillin challenge). Participants will be randomised 1:1 to the intervention arm (direct oral penicillin challenge) or standard of care arm (skin testing followed by oral penicillin challenge, if skin testing is negative). The sample size of 380 randomised patients (190 per treatment arm) is required to demonstrate non-inferiority.

ETHICS AND DISSEMINATION

The study will be performed according to the guidelines of the Helsinki Declaration and is approved by the Austin Health Human Research Ethics Committee (HREC/62425/Austin-2020) in Melbourne Australia, Vanderbilt University Institutional Review Board (IRB #202174) in Tennessee, USA, Duke University Institutional Review Board (IRB #Pro00108461) in North Carolina, USA and McGill University Health Centre Research Ethics Board in Canada (PALACE/2022-7605). The results of this study will be published and presented in various scientific forums.

TRIAL REGISTRATION NUMBER

NCT04454229.

The Impact of Reported β-Lactam Allergy on Clinical Outcomes and Antibiotic Use Among Solid Organ Transplant Recipients

Background

Reported β-lactam allergies (BLAs) are common and frequently inaccurate, but there are limited data on the clinical implications of BLA among solid organ transplant (SOT) recipients. We examined the impact of BLA on clinical outcomes and antibiotic use among SOT recipients.

Methods

This retrospective cohort study included adult patients undergoing single-organ heart, kidney, liver, lung, or pancreas transplant at a United States academic medical center from 1 April 2017 to 31 December 2020. Demographic and clinical data were collected from the electronic health record. Multivariate median regression was performed to evaluate the association between BLA and days alive and out of the hospital in the first 180 days posttransplant (DAOH180). Multivariate logistic regression was performed to evaluate the association between BLA and antibiotic use.

Results

Among 1700 SOT recipients, 285 (16.8%) had a BLA at the time of transplant. BLA was not associated with DAOH180 (adjusted median difference, -0.8 days [95% confidence interval {CI}, -2.7 to 1.2]; P = .43). Patients with BLA were more likely to receive intravenous vancomycin (adjusted odds ratio [aOR], 1.8 [95% CI, 1.3-2.6]; P < .001), clindamycin (aOR, 9.9 [95% CI, 5.1-18.9]; P < .001), aztreonam (aOR, 19.6 [95% CI, 5.9-64.4]; P < .001), fluoroquinolones (aOR, 3.8 [95% CI, 2.8-5.0]; P < .001), or aminoglycosides (aOR, 3.9 [95% CI, 2.5-6.2]; P < .001).

Conclusions

BLA was associated with use of β-lactam alternative antibiotics but not DAOH180 among SOT recipients.

Association of antibiotic allergy labels with hospital length of stay

BACKGROUND

Many antibiotic allergy labels (AAL) are invalid. Excluding true allergy in people with AAL ("delabeling") could improve health outcomes and decrease costs. Several studies with limited covariate adjustment have associated AAL with a prolonged hospital length of stay (LOS).

OBJECTIVE

This study determined whether AAL's association with LOS persisted after extensive adjustment for potential confounders and covariates.

METHODS

All nonpsychiatric admissions to a tertiary care teaching hospital from 2012 to 2015 were included. Generalized estimating equation methods were used to model the daily discharge likelihood as a function of AAL and other important factors (death risk score, daily discharge score, daily severity of illness score, antibiotic use, hospital day and location, weekend-holiday status, and service).

RESULTS

A total of 111,611 admissions (76,460 patients) were studied, in which 16,489 (14.8%) had recorded AAL. Patients with an AAL had a notably greater disease burden: they were older and had more comorbidities, greater health system utilization, and higher death risk. In the univariate analysis, AAL was associated with a significantly decreased daily discharge likelihood (odds ratio [OR], 0.93; [95% confidence interval, 0.90-0.95]). After adjustment for potential confounders and covariates, AAL was not associated with daily discharge likelihood (adjusted OR [aOR] without antibiotics: 1.00 [0.98-1.03]; aOR with antibiotics: 1.02 [0.99-1.04]). Similar results were also seen with penicillin AAL (aOR without antibiotics: 0.99 [0.95-1.02]; aOR with antibiotics: 1.00 [0.96-1.03]).

CONCLUSION

Antibiotic allergy label was strongly associated with a greater disease burden. After adjusting for important covariates, our analysis found no significant association between AAL and hospital LOS.

Impact of an inpatient nurse-initiated penicillin allergy delabeling questionnaire

Penicillin allergy delabeling is an important component of antimicrobial stewardship and improves patient outcomes. We demonstrated the successful use of a nurse-initiated questionnaire to remove inappropriate penicillin allergy labels in inpatients. Nurses can play a key role in improving antibiotic allergy assessment and more broadly in interprofessional antimicrobial stewardship.

Infection prevention requirements for the medical care of immunosuppressed patients: recommendations of the Commission for Hospital Hygiene and Infection Prevention (KRINKO) at the Robert Koch Institute

In Germany, guidelines for hygiene in hospitals are given in form of recommendations by the Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention, "KRINKO"). The KRINKO and its voluntary work are legitimized by the mandate according to § 23 of the Infection Protection Act (Infektionsschutzgesetz, "IfSG"). The original German version of this document was published in February 2021 and has now been made available to the international professional public in English. The guideline provides recommendations on infection prevention and control for immunocompromised individuals in health care facilities. This recommendation addresses not only measures related to direct medical care of immunocompromised patients, but also management aspects such as surveillance, screening, antibiotic stewardship, and technical/structural aspects such as patient rooms, air quality, and special measures during renovations.

Promoting β-lactam utilization through suppression of electronic medical record cross-allergy alerts

DISCLAIMER

In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these 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.

PURPOSE

Current literature surrounding management of patients with reported β-lactam allergies focuses on allergy delabeling. Standard clinical decision support tools have not been optimized to be compatible with the currently accepted cross-reaction rate of 1% to 2%. This potentially promotes use of non-β-lactam antibiotics, which are often not first-line therapy and may carry increased risks. The impact of electronic medical record (EMR) clinical decision support tool optimization on utilization of β-lactam antibiotics in β-lactam-allergic patients was evaluated.

METHODS

A retrospective pre-post β-lactam cross-allergy EMR alert suppression quality improvement intervention cohort study of β-lactam-allergic adult inpatients prescribed antibiotics was conducted. Preintervention baseline data were collected for an initial cohort admitted during September 2018. The intervention, in which clinical decision support rules were updated to display β-lactam cross-sensitivity allergy alerts only for β-lactam-allergic patients with documentation of organization-defined high-severity reactions of anaphylaxis, hives, and shortness of breath, was implemented August 20, 2019. The postintervention cohort included patients admitted during September 2019.

RESULTS

A 91% increase in the percentage of β-lactam-allergic patients who received a β-lactam agent at any time during their admission was noted after the intervention (26.6% vs 51%, P < 0.001). Statistically significant decreases in prescribing of alternative antibiotic classes were seen for fluoroquinolones (decrease from 45.3% to 26%, P < 0.001), aminoglycosides (decrease from 9.4% to 2.9%, P = 0.002), and aztreonam (decrease from 30% to 16.7%, P < 0.001).

CONCLUSION

EMR β-lactam cross-allergy alert optimization consistent with current literature significantly improved the utilization of alternative β-lactam subclasses, mostly through β-lactam prescribing as initial therapy in β-lactam-allergic patients.

Drug Allergy Delabeling Programs: Recent Strategies and Targeted Populations

Drug allergy delabeling programs have become an essential element of antibiotic stewardship. Development of delabeling programs involves careful selection of target patient population, thoughtful design of delabeling approach, stakeholder engagement, assembly of key team members, implementation, and evaluation of clinical and safety outcomes. Recent programs have targeted patients thought to be most likely to benefit from removal of inaccurate antibiotic allergy labels, those with β-lactam antibiotic allergies and high-risk populations likely to need β-lactam antibiotics as first-line treatment. This review provides an overview of current risk stratification methods and β-lactam cross-reactivity data and summarizes how different inpatient and outpatient delabeling programs have used these concepts in delabeling algorithms. β-Lactam delabeling programs for inpatients, pediatric patients, and programs utilizing telehealth have been implemented with good outcomes. This review also focuses on delabeling programs for high-risk populations likely to benefit from first-line β-lactam antibiotics. These populations include perioperative, prenatal, and immunocompromised patients. Delabeling programs have been successful in the inpatient and outpatient settings at enabling appropriate antibiotic use. This article reviews delabeling strategies utilized by these programs with a focus on highlighting elements key to their success and future areas for innovation.

A Continuing Education Activity Durably Addressed Knowledge Gaps Related to Penicillin Allergies Among Pharmacists and Pharmacy Technicians

Background: Penicillin allergy is one of the most frequent self-reported allergies; however, only about 10% of reported allergies are accurate. Objectives: Through the creation of a continuing pharmacy education (CPE) activity, we sought to assess knowledge gaps and comfort levels in the management of penicillin allergies. Methods: A 1-hour enduring-content CPE activity was offered as an interactive course from September 20, 2019, to September 20, 2020. Participants completed 3 surveys (pre-survey, post-survey, and follow-up survey). Participants were pharmacists and pharmacy technicians who completed, at a minimum, the activity and both pre- and post-surveys. The primary outcome was the percentage of participants scoring >80% on knowledge-based questions on the post-survey compared with the pre-survey. Secondary outcomes included pre-post comparisons on knowledge-based questions, participants’ self-report of an allergy, and comfort levels dispensing cephalosporins in a patient with a self-reported penicillin allergy. Results: A total of 389 participants completed the CPE activity, with 176 included for analysis. Significantly more participants scored >80% on knowledge-based questions on the post-survey compared with the pre-survey (71.6% vs 22.7%, P < .001). There was no significant difference between the percentage of participants scoring >80% on the post-survey and the follow-up survey (71.6% vs 65%, P = .119). The majority of participants (74%) felt comfortable dispensing a cephalosporin in a patient with a penicillin allergy on the pre-survey, with similar percentages on the post- and follow-up surveys (77% and 90%, respectively). Conclusion: A targeted continuing education program improved overall knowledge, which was sustained for up to 2 months.

Immediate and Delayed Hypersensitivity Reactions to Beta-Lactam Antibiotics

Beta-lactam antibiotics are the most commonly reported drug allergy in adults and children. More than 95% of those with reported allergy labels to beta lactams are not confirmed when subjected to allergy testing. Beta lactam antibiotics are associated with a wide spectrum of immediate and delayed drug hypersensitivity reactions. The latency period to symptoms and clinical presentation aids in the causality assessment. Risk stratification based on diagnosis and timing then allows for appropriate management and evaluation. Skin prick testing, intradermal testing and oral challenge are well established for evaluation of immediate reactions. Delayed intradermal testing, patch testing and oral challenge can also be considered for evaluation of mild to moderate delayed reactions. Cross-reactivity between beta-lactams appears to be driven most commonly by a shared R1 side-chain. Standardized algorithms, protocols and pathways are needed for widespread implementation of a pragmatic and effective approach to patients reporting beta lactam allergy.

Burden of antibiotic allergy labels in Australian aged care residents: Findings from a national point-prevalence survey

OBJECTIVE

To determine the prevalence of antibiotic allergy labels (AALs) in Australian aged care residents and to describe the impact of labels on antibiotic prescribing practices.

DESIGN

Point-prevalence survey.

SETTING

Australian residential aged care facilities.

PARTICIPANTS

We surveyed 1,489 residents in 407 aged care facilities.

METHODS

Standardized data were collected on a single day between June 1 and August 31, 2018, for residents prescribed an antibiotic. An AAL was reported if it was documented in the resident's health record. Resident-level data were used to calculate overall prevalence, and antibiotic-level data were used to report relative frequency of AALs for individual antibiotics and classes.

RESULTS

Among 1,489 residents, 356 (24%) had 1 or more documented AALs. The AALs for penicillin (28.3%), amoxicillin or amoxicillin/clavulanic acid (10.5%), cefalexin (7.2%), and trimethoprim (7.0%) were most commonly reported. The presence of an AAL was associated with significantly less prescribing of penicillins (OR, 0.43; 95% CI, 0.31-0.62; P < .001) and significantly more prescribing of lincosamides (OR, 4.81; P < .001), macrolides (OR, 2.03; P = .007), and tetracyclines (OR, 1.54; P = .033). Of residents with AALs, 7 residents (1.9%) were prescribed an antibiotic that was listed on the allergy section of their health record.

CONCLUSIONS

A high prevalence of AALs was observed among residents of Australian aged care facilities, comparable to the prevalence of AALs in high-risk hospitalized patients. Significant increases in prescribing of lincosamide, macrolide, and tetracycline agents poses a potential risk to aged populations, and future studies must evaluate the benefits of AAL delabelling programs tailored for aged care settings.

Beta-lactam allergy labeling in intensive care units: An observational, retrospective study

ABSTRACT

This retrospective study aimed to describe the association between the "β-lactam allergy" labeling (BLAL) and the outcomes of a cohort of intensive care unit (ICU) patients.Retrospective cohort study.Seven ICU of the Aix Marseille University Hospitals from Marseille in France.We collected the uses of the label "β-lactam allergy" in the electronic medical files of patients aged 18 years or more who required more than 48 hours in the ICU with mechanical ventilation and/or vasopressors admitted to 7 ICUs of a single institution.We retrospectively compared the patients with this labeling (BLAL group) with those without this labeling (control group).The primary outcome was the duration of ICU stay. Among the 7146 patients included in the analysis, 440 and 6706 patients were classified in the BLAL group and the control group, respectively. The prevalence of BLAL was 6.2%. In univariate and multivariate analyses, BLAL was weakly or not associated with the duration of ICU and hospital stays (respectively, 6 [3-14] vs 6 [3-14] days, standardized beta -0.09, P = .046; and 18 [10-29] vs 15 [8-28] days, standardized beta -0.09, P = .344). In multivariate analysis, the ICU and 28-day mortality rates were both lower in the BLAL group than in the control group (aOR 0.79 95% CI [0.64-0.98] P = .032 and 0.79 [0.63-0.99] P = .042). Antibiotic use differed between the 2 groups, but the outcomes were similar in the subgroups of septic patients in the BLAL group and the control group.In our cohort, the labeling of a β-lactam allergy was not associated with prolonged ICU and hospital stays. An association was found between the labeling of a β-lactam allergy and lower ICU and 28-day mortality rates.Trial registration: Retrospectively registered.

Prevalence of drug allergy in South Australia

INTRODUCTION

Drug allergy is commonly reported in patient notes and electronic health records. The prevalence of self-reported drug allergy in the general Australian population has not previously been studied.

METHODS

We surveyed a representative sample of the South Australian adult population regarding their own perception of drug allergy, including drug type and severity as well as the use of medical alert devices. Data were weighted to correspond to age and sex of the South Australian population.

RESULTS

22.2% of adults in South Australia consider themselves allergic to one or more drugs, 9.3% declared themselves to be allergic to penicillin, 5% to an antibiotic other than penicillin, and 13% to one or more antibiotics. Drug allergy and penicillin allergy was significantly more prevalent in females, and increased with age. Thirteen percent of those with an antibiotic allergy reported a severe reaction, of whom 27% wore a medical notification device. Of those allergic to penicillin, 75% had their index reaction more than 10 years ago and did not report severe features.

DISCUSSION

Self-reported drug allergy is common in the general population, as it is in medical clinic and hospital populations. The majority of those reporting penicillin allergy would be considered low-risk and suitable for delabelling procedures. This article is protected by copyright. All rights reserved.

Empiric aztreonam is associated with increased mortality compared to beta-lactams in septic shock

PURPOSE

To determine if aztreonam as initial empiric treatment of adult septic shock is associated with increased mortality compared to the use of anti-pseudomonal beta-lactam agents.

METHODS

This was a multicenter, retrospective cohort study of 582 adult emergency department patients admitted to 12 acute care facilities within a single health system from January 2014 to December 2017 with septic shock receiving either aztreonam or an anti-pseudomonal beta-lactam for empiric treatment and discharged with an infection-related ICD-9 or ICD-10 code. The primary endpoint was in-hospital mortality.

RESULTS

Initial exposure to aztreonam was associated with increased hospital mortality compared to treatment with an anti-pseudomonal beta-lactam agent (22.7% vs. 12.9%, OR = 1.98, 95% CI: 1.27-3.11). When adjusted for APACHE II score, the treatment group effect on mortality remained statistically significant (OR = 1.74, 95% CI: 1.08-2.80). Aztreonam use was also associated with increased utilization of aminoglycosides (28.9% vs. 12.4%, p < 0.0001) and fluoroquinolones (50.5% vs. 25.8%, p < 0.01). There was no difference in hospital or intensive care unit length of stay in surviving patients between the two groups.

CONCLUSIONS

Compared to anti-pseudomonal beta-lactams, empiric treatment with aztreonam is associated with increased mortality and greater antibiotic exposure among patients with acute septic shock. These findings suggest that treatment with anti-pseudomonal beta-lactams should be prioritized over allergy avoidance whenever feasible.

Evaluation of a Pharmacist-Led Penicillin Allergy Assessment Program and Allergy Delabeling in a Tertiary Care Hospital

IMPORTANCE

Penicillin allergies are frequently mislabeled, which may contribute to use of less-preferred alternative antibiotics.

OBJECTIVE

To evaluate a pharmacist-led allergy assessment program's association with antimicrobial use and clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A pharmacist-led allergy assessment program was launched in 2 phases (June 1, 2015, and November 2, 2016) at a single-center tertiary referral hospital. The longitudinal cross-sectional study included all study period adult admissions; hospitalwide outcomes were assessed by segmented regression. Individual outcomes were assessed within an embedded propensity score-matched case-control study of inpatients undergoing comprehensive allergy assessment following self-report of penicillin allergy. Analysis occurred from March 1, 2020, to February 29, 2020.

EXPOSURES

The longitudinal study analyzed hospital-level outcomes over 3 periods: preintervention (15 months), phase 1 (structured allergy history alone, 16 months), and phase 2 (comprehensive assessment including penicillin skin testing, 52 months). The case-control study defined cases as individuals undergoing comprehensive allergy assessment.

MAIN OUTCOMES AND MEASURES

Hospital-level outcomes included antibiotic days of therapy per 1000 patient-days and hospital-acquired Clostridioides difficile infection (CDI) incidence per 10 000 patient-days. Individual outcomes included antibiotic selection, overall survival, and CDI-free survival.

RESULTS

Longitudinal analysis spanned 2014-2020 (median admissions, 46 416 per year; interquartile range [IQR], 46 001-50 091 per year). Hospitalwide, allergy histories were temporally associated with decreased use of nonpenicillin alternative antibiotics (rate ratio, 0.87; 95% CI, 0.79-0.97) and high-CDI-risk antibiotics (rate ratio, 0.91; 95% CI, 0.85-0.98). Penicillin skin testing was temporally associated with lower hospital-acquired CDI rates (rate ratio, 0.61; 95% CI, 0.43-0.86). The embedded case-control study included 272 cases and 819 controls. Median age was 63 years (interquartile range, 51-73 years), 553 (50.7%) patients were women, and 229 (21.0%) patients were Black. Allergy-assessed patients were less likely to receive high-CDI-risk antibiotics at discharge (odds ratio, 0.66; 95% CI, 0.44-0.98). Estimated reductions in mortality (hazard ratio, 0.77; 95% CI, 0.55-1.07) and hospital-acquired CDI risk (hazard ratio, 0.53; 95% CI, 0.18-1.55) were not statistically significant.

CONCLUSIONS AND RELEVANCE

Pharmacist-led allergy assessments may be associated with reduced high-CDI-risk antibiotic use at both hospitalwide and individual levels. Although individual reductions in mortality and CDI risk did not achieve significance, divergence of survival curves suggest longer-term benefits of allergy delabeling warrant future study.

Penicillin Allergy Testing Is Cost-Saving: An Economic Evaluation Study

BACKGROUND

Having a penicillin allergy label is associated with the use of less appropriate and more expensive antibiotics and increased healthcare utilization. Penicillin allergy testing results in delabeling most allergy claimants and may be cost-saving. This study aimed to project whether penicillin allergy testing in patients reporting a penicillin allergy is cost-saving.

METHODS

In this economic evaluation study, we built decision models to project the economic impact of 2 strategies for a patient with a penicillin allergy label: (1) perform diagnostic testing (drug challenges, with or without skin tests); and (2) do not perform diagnostic testing. The health service perspective was adopted, considering costs with penicillin allergy tests, and with hospital bed-days/outpatient visits, antibiotic use, and diagnostic testing. Twenty-four base case decision models were built, accounting for differences in the diagnostic workup, setting (inpatient vs outpatient) and geographic region. Uncertainty was explored via probabilistic sensitivity analyses.

RESULTS

Penicillin allergy testing was cost-saving in all decision models built. For models assessing the performance of both skin tests and drug challenges, allergy testing resulted in average savings (in United States [US] dollars) of $657 for inpatients (US: $1444; Europe: $489) and $2746 for outpatients (US: $256; Europe: $6045). 75% of simulations obtained through probabilistic sensitivity analysis identified testing as the less costly option.

CONCLUSIONS

Penicillin allergy testing was projected to be cost-saving across different scenarios. These results are devised to inform guidelines, supporting the adoption of policies promoting widespread testing of patients with a penicillin allergy label.

Amoxicillin oral provocation challenge in a primary care clinic: a descriptive analysis

BACKGROUND

Penicillin is the most frequently reported drug allergen; however, most of these allergies are not true allergies and do not justify the prescription of alternative, less effective and more expensive antibiotic drugs. We aimed to show that patients at low risk of amoxicillin allergy can safely and efficiently undergo oral provocation challenge (OPC) by their primary care physician.

METHODS

In this descriptive analysis, we conducted a retrospective chart review of all primary care patients who had undergone OPC from November 2017 to October 2019 in the Amoxicillin Allergy Clinic at the North Perth Family Health Team, Listowel, Ontario. Eligibility for OPC among patients 18 months and older was determined through review of a self-reported patient intake form asking about symptoms, onset, duration, history and family history of allergic reactions, as well as the patient's electronic medical record. Patients were considered to be at low risk of true penicillin allergy if there was no history of anaphylaxis or severe cutaneous reactions. Those with low-risk allergic reactions returned for testing with an OPC to amoxicillin. We collected data on clinical characteristics, antibiotic exposure, parental drug allergy, response to OPC and wait time from referral. We used t tests to describe and compare these variables. Our primary outcome was reaction to OPC by severity as categorized by the World Allergy Organization grading system. Our secondary outcome was the time from referral to completed testing.

RESULTS

In total, we included 99 patients (mean age 28.3, standard deviation [SD] 21.2 yr); 72 (73%) were female. Of those tested, 97% (n = 96) completed the OPC with no reaction, 3% (n = 3) had mild immediate reactions, and no serious immediate reactions developed. Mean wait time to testing was 59.0 (SD 69.8) days, with a median (interquartile range) of 39.5 (13.5-70.0) days.

INTERPRETATION

Oral provocation challenge presents a safe and accessible opportunity for primary care providers to address erroneous allergy labels to penicillin and related drugs within the primary care office setting. There could be positive public health implications if OPC to penicillin drugs is implemented in primary care.

Prevalence of Antibiotic Allergy Labels in a Tertiary Referral Center in Belgium

BACKGROUND

Antibiotic (AB) allergies are among the most frequently occurring adverse drug reactions. In US literature, AB allergy labels (AAL) are reported in 10% to 15% of patients' charts; however, large-scale European analyses are scarce.

OBJECTIVES

To retrospectively assess the prevalence of AAL in a tertiary referral hospital in Belgium between 2010 and 2018.

METHODS

Patients who consulted and/or were hospitalized during the study period, who had been labeled with an AB allergy, were selected for further analysis.

RESULTS

Of 1,009,598 unique patients (outpatients, n = 736,469; inpatients, n = 273,129), 28,147 patients (3%) were registered with 1 or more AAL, being 1% of outpatients (n = 9562) and 7% of inpatients (n = 18,585). Women were more likely to carry an AAL (68%) compared with men (32%, P < .001). In patients with an AAL, 9% had multiple labels and 5% had labels for multiple AB classes. Most frequently, beta-lactams were involved (84% of AAL), followed by quinolones (7%) and sulfonamides and macrolides (both 3%). Moreover, 88% of the reactions were self-reported, mostly being an unspecified rash (53%), whereas only 3% were considered confirmed AAL.

CONCLUSION

With an overall prevalence of 3%, the burden of AAL is less in our Western European center compared with US reports. However, this prevalence most likely still represents an overestimation of genuine AB allergic patients because most labels lack confirmation and/or specifications. Our work indicates that knowledge of the local epidemiology of AAL is necessary to estimate the impact of better allergy labeling and delabeling strategies.

High-cost, high-need patients: the impact of reported penicillin allergy

OBJECTIVES

More than 90% of patients who report a penicillin allergy have the allergy disproved when tested. Unnecessary use of alternative (non-beta-lactam) antibiotics can result in more treatment failures and adverse reactions. We described the prevalence and impact of a reported penicillin allergy in high-cost, high-need (HCHN) patients.

STUDY DESIGN

Retrospective cohort.

METHODS

We identified HCHN patients in a care management program of an urban academic medical center (January 1, 2014, to December 31, 2016). We used multivariable logistic regression models to determine the association between a reported penicillin allergy and antibiotic use. We used multivariable Poisson regression models to determine the association between a reported penicillin allergy, with or without multiple drug intolerance syndrome (MDIS; ≥3 reported drug allergies), and healthcare resource utilization (HRU).

RESULTS

Of 1870 HCHN patients, 383 (20%) reported penicillin allergy, 835 (45%) had MDIS, and 290 (16%) had both. HCHN patients reporting penicillin allergy had an increased odds of beta-lactam alternative antibiotic use (adjusted odds ratio, 3.84; 95% CI, 2.17-6.80). HRU was significantly higher for patients reporting a penicillin allergy alone (adjusted relative risk [aRR], 1.13; 95% CI, 1.03-1.25) and with concurrent MDIS (aRR, 1.20; 95% CI, 1.08-1.34).

CONCLUSIONS

HCHN patients had a high burden of reported drug allergy. A reported penicillin allergy conferred a 4-fold increased odds of beta-lactam alternative antibiotic use. Reporting penicillin allergy, with and without MDIS, was associated with significantly more HRU. HCHN care management programs should consider systematic drug allergy evaluations to optimize antibiotic use in these fragile patients.

[Less is more… in infectious diseases]

BACKGROUND

The increasing development of antimicrobial resistance has been identified as one of the greatest threats to public health and is caused to a relevant extent by falsely indicated antibiotic treatment.

OBJECTIVE

The main aim of this article is to identify areas in infectious disease diagnostics and treatment where overuse occurs and to provide recommendations on how to avoid it.

MATERIAL AND METHODS

The authors identified current and relevant studies on the topic of medical overuse in infectious diseases via a literature search. In particular, contributions from international "less is more" initiatives were included. The focus was on areas in which a reduction of diagnostic and therapeutic measures leads to an optimization of patient outcomes.

RESULTS

In many cases overuse in the context of diagnostics and treatment of infectious diseases not only leads to an unnecessary financial burden on the healthcare system and is not beneficial but can also increase the risk of development of antimicrobial resistance and have adverse consequences for patients.

CONCLUSION

Correct indications as well as focused selection and adequate application of antimicrobial agents is crucial to provide the best possible medical care. Diagnostic and antibiotic stewardship measures, which should be implemented in collaboration with infectious disease specialists, can help to identify and reduce areas of overuse and misuse.

Reported β-Lactam and Other Antibiotic Allergies in Solid Organ and Hematopoietic Cell Transplant Recipients

BACKGROUND

Patients with reported β-lactam antibiotic allergies (BLAs) are more likely to receive broad-spectrum antibiotics and experience adverse outcomes. Data describing antibiotic allergies among solid organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients are limited.

METHODS

We reviewed records of adult SOT or allogeneic HCT recipients from 1 January 2013 to 31 December 2017 to characterize reported antibiotic allergies at time of transplantation. Inpatient antibiotic use was examined for 100 days posttransplant. Incidence rate ratios (IRRs) comparing antibiotic use in BLA and non-BLA groups were calculated using multivariable negative binomial models for 2 metrics: days of therapy (DOT) per 1000 inpatient days and percentage of antibiotic exposure-days.

RESULTS

Among 2153 SOT (65%) and HCT (35%) recipients, 634 (29%) reported any antibiotic allergy and 347 (16%) reported BLAs. Inpatient antibiotics were administered to 2020 (94%) patients during the first 100 days posttransplantation; average antibiotic exposure was 41% of inpatient-days (interquartile range, 16.7%-62.5%). BLA patients had significantly higher DOT for vancomycin (IRR, 1.4 [95% confidence interval {CI}, 1.2-1.7]; P < .001), clindamycin (IRR, 7.6 [95% CI, 2.2-32.4]; P = .001), and aztreonam in HCT (IRR, 9.7 [95% CI, 3.3-35.0]; P < .001), and fluoroquinolones in SOT (IRR, 2.9 [95% CI, 2.1-4.0]; P < .001); these findings were consistent when using percentage of antibiotic exposure-days.

CONCLUSIONS

Transplant recipients are frequently exposed to antibiotics and have a high prevalence of reported antibiotic allergies. Reported BLA was associated with greater use of β-lactam antibiotic alternatives. Pretransplant antibiotic allergy evaluation may optimize antibiotic use in this population.

The impact of antibiotic allergy labels on antibiotic exposure, clinical outcomes, and healthcare costs: A systematic review

OBJECTIVE

A growing body of evidence suggests that antibiotic allergy labels as documented in medical records are a risk factor for poor clinical outcomes. In this systematic review, we aimed to determine how antibiotic allergy labels influence 3 domains: antibiotic use and exposure, clinical outcomes, and healthcare-related costs.

DESIGN

We performed a systematic review to identify studies reporting outcomes in patients with antibiotic allergy labels compared to nonallergic counterparts. The search included PubMed, EMBASE, Cochrane CENTRAL, EBSCO, Cochrane Database of Abstracts of Reviews of Effects and Web of Science. Two reviewers independently screened studies for inclusion and abstracted data. Studies were graded using the Newcastle-Ottawa quality assessment scale. Study outcomes included antibiotic use, clinical outcomes, and economic outcomes.

RESULTS

In total, 41 studies met our criteria for inclusion. These studies varied in medical specialty, patient population, healthcare delivery system, and design, but most were conducted among adults age >18 years (85%) in the inpatient setting (82.5%). Among 34 studies examining antibiotic exposure, 32 (94%) found that patients with antibiotic allergy labels received more broad-spectrum antibiotics. Moreover, 31 studies examined clinical outcomes such as length of hospitalization, ICU admission, hospital readmission, multidrug-resistant or opportunistic infection, or mortality, and 27 (87%) found that allergy-labeled patients had at least 1 negative outcome. Of 9 studies examining healthcare costs, 7 (78%) found that allergy-labeled patients incurred significantly higher drug or hospital-related costs.

CONCLUSIONS

Antibiotic allergy labels have negative effects on antibiotic use, clinical outcomes, and economic outcomes in a variety of clinical settings and populations.

Assessing mortality outcomes of beta-lactam-allergic patients presenting with sepsis

OBJECTIVE

To determine the impact of reported beta-lactam allergies on in-hospital mortality and other clinical outcomes in patients who presented with severe sepsis or septic shock.

METHODS

This single-center, retrospective cohort study was performed at a 35-bed emergency department in central Kentucky. Patients presenting with sepsis, aged 18years or older, were identified between October 2016 and June 2017.

RESULTS

438 patients with severe sepsis and/or septic shock were identified. Rates of the combined endpoint of in-hospital mortality or transfer to hospice were similar in patients with a beta-lactam allergy (7.2%) versus those with no reported beta-lactam allergy (10.4%) (p=0.41). Time to initiation of antibiotic therapy was slightly longer in the beta-lactam allergic group (2.2h) versus those with no reported beta-lactam allergy (2.15h), but the difference was not statistically significant (p=0.993). Patients were 20.9% more likely to receive an appropriate empiric antibiotic, based off of retrospective culture review, if they did not report a beta-lactam allergy (p=0.009). This led to a delay in effective therapy of 1.59h in the reported beta-lactam allergy arm (p=0.037).

CONCLUSIONS

Adequate documentation of beta-lactam allergies is vital to ensure timely and appropriate treatment in patients presenting with severe sepsis and septic shock. Choosing alternative treatment options results in increased time to effective antibiotics, reduced likelihood of covering cultures with first antibiotic, and increased total hospital and variable direct cost.

New Avenues for Antimicrobial Stewardship: The Case for Penicillin Skin Testing by Pharmacists

It is well-appreciated that patients with documented penicillin allergies often receive broader-spectrum antibiotics. This practice has been associated with increased antimicrobial resistance and cost. In recent years, considerable efforts have been made to spread awareness on the implications of self-reported penicillin allergies. The use of penicillin skin testing to evaluate for true allergies has been strongly recommended by major organizations for decades. However, testing remains underutilized. Current literature has suggested various models of incorporating penicillin allergy screening and testing by different healthcare practitioners (ie, physicians, allergists, nurses, pharmacists). We suggest broader adoption for the role of pharmacists in the provision of penicillin skin testing. This would help expand the service and maximize the potential benefits of penicillin skin testing.