Heterogeneity of Drug Allergies and Reaction Lists in Two U.S. Health Care Systems' Electronic Health Records.

BACKGROUND: Health care institutions have their own "picklist" for clinicians to document adverse drug reactions (ADRs) into the electronic health record (EHR) allergy list. Whether the lack of a nationally standardized picklist impacts clinician data entries is unknown. OBJECTIVES: The objective of this study was to assess the impact of defined reaction picklists on clinical documentation and, therefore, downstream analytics and clinical research using these data at two institutions. METHODS: ADR data were obtained from the EHRs of patients who visited the emergency department or outpatient clinics at Brigham and Women's Hospital (BWH) and University of Colorado Hospital (UCH) from 2013 to 2018. Reported drug class ADR prevalences were calculated. We investigated the reactions on each picklist and compared the top 40 reactions at each institution, as well as the top 10 reactions within each drug class. RESULTS: Of 2,160,116 patients, 640,444 (30%) had 928,973 active drug allergies. The most commonly reported drug class allergens were similar between BWH and UCH. BWH's picklist had 48 reactions, and UCH's had 160 reactions; 29 reactions were shared by both picklists. While the top four reactions overall (rash, GI upset/nausea/vomiting, hives, itching) were identical between sites, reactions by drug class exhibited greater documentation diversity. For example, while the summed prevalence of swelling-related reactions to angiotensin-converting-enzyme inhibitors was comparable across sites, swelling was represented by two terms ("swelling," "angioedema") at BWH but 11 terms at UCH (e.g., "swelling," "edema," by body locality). CONCLUSION: The availability and granularity of reaction picklists impact ADR documentation in the EHR by health care providers; picklists may partially explain variations in reported ADRs across health care systems.

Association of Self-reported High-Risk Allergy History With Allergy Symptoms After COVID-19 Vaccination.

Importance: Allergic history in individuals with confirmed anaphylaxis to a messenger RNA (mRNA) COVID-19 vaccine is common. However, the risk factors for allergy symptoms after receiving the vaccine are unknown. Objective: To assess the association between self-reported history of high-risk allergy and self-reported allergic reactions after mRNA COVID-19 vaccination of health care employees. Design, Setting, and Participants: This cohort study obtained demographic, medical, and vaccine administration data of employees of Mass General Brigham from the institutional electronic health record. Employees who received at least 1 dose of an mRNA COVID-19 vaccine between December 14, 2020, and February 1, 2021, and who completed at least 1 postvaccination symptom survey in the 3 days after vaccination were included. Exposures: Self-reported history of high-risk allergy, defined as a previous severe allergic reaction to a vaccine, an injectable medication, or other allergen. Main Outcomes and Measures: The primary outcome was 1 or more self-reported allergic reactions in the first 3 days after dose 1 or dose 2 of an mRNA COVID-19 vaccine. Multivariable log binomial regression was used to assess the association between allergic reactions and high-risk allergy status. Results: A total of 52 998 health care employees (mean [SD] age, 42 [14] years; 38 167 women [72.0%]) were included in the cohort, of whom 51 706 (97.6%) received 2 doses of an mRNA COVID-19 vaccine and 474 (0.9%) reported a history of high-risk allergy. Individuals with vs without a history of high-risk allergy reported more allergic reactions after receiving dose 1 or 2 of the vaccine (11.6% [n = 55] vs 4.7% [n = 2461]). In the adjusted model, a history of high-risk allergy was associated with an increased risk of allergic reactions (adjusted relative risk [aRR], 2.46; 95% CI, 1.92-3.16), with risk being highest for hives (aRR, 3.81; 95% CI, 2.33-6.22) and angioedema (aRR, 4.36; 95% CI, 2.52-7.54). Conclusions and Relevance: This cohort study found that self-reported history of high-risk allergy was associated with an increased risk of self-reported allergic reactions within 3 days of mRNA COVID-19 vaccination. However, reported allergy symptoms did not impede the completion of the 2-dose vaccine protocol among a cohort of eligible health care employees, supporting the overall safety of mRNA COVID-19 vaccine.

Association of Penicillin or Cephalosporin Allergy Documentation and Antibiotic Use in Hospitalized Patients with Pneumonia.

BACKGROUND: Treatment guidelines for pneumonia recommend beta-lactam antibiotic-based therapy. Although reported penicillin allergy is common, more than 90% of patients with reported penicillin allergy are not allergic. OBJECTIVE: We evaluated the association of a documented penicillin and/or cephalosporin (P/C) allergy to antibiotic use for the treatment of inpatient pneumonia. METHODS: This was a national cross-sectional study conducted among Vizient, Inc., network hospitals that voluntarily contributed data. Among hospitalized patients with pneumonia, we examined the relation of a documented P/C allergy in the electronic health record to prevalence of first-line beta-lactam antibiotic administration and alternative antibiotics using multivariable log-binomial regression with generalized estimating equations. RESULTS: Of 2,276 inpatients receiving antibiotics for pneumonia at 95 U.S. hospitals, 450 (20%) had a documented P/C allergy. Compared with pneumonia patients without a documented P/C allergy, patients with a documented P/C allergy had reduced prevalence of first-line beta-lactam antibiotic use (adjusted prevalence ratio [aPR] 0.79; 95% confidence interval [95% CI] 0.69-0.89]). Patients with high-risk P/C reactions (n = 91) had even lower prevalence of first-line beta-lactam antibiotic use (aPR 0.47; 95% CI 0.35-0.64). Alternative antibiotics associated with a higher use in pneumonia patients with a documented P/C allergy included carbapenems (aPR 1.61; 95% CI 1.22-2.13) and fluoroquinolones (aPR 1.52; 95% CI 1.21-1.91). CONCLUSIONS: Inpatients with documented P/C allergy and pneumonia were less likely to receive recommended beta-lactams and more likely to receive carbapenems and fluoroquinolones. Inpatient allergy assessment may improve optimal antibiotic therapy for the 20% of inpatients with pneumonia and a documented P/C allergy.

Assessment of the Frequency of Dual Allergy to Penicillins and Cefazolin: A Systematic Review and Meta-analysis.

Importance: Cefazolin is the preoperative antibiotic of choice because it is safer and more efficacious than second-line alternatives. Surgical patients labeled as having penicillin allergy are less likely to prophylactically receive cefazolin and more likely to receive clindamycin or vancomycin, which results in higher rates of surgical site infections. Objective: To examine the incidence of dual allergy to cefazolin and natural penicillins. Data Sources: MEDLINE/PubMed, Web of Science, and Embase were searched without language restrictions for relevant articles published from database inception until July 31, 2020. Study Selection: In this systematic review and meta-analysis, a search of MEDLINE/PubMed, Web of Science, and Embase was performed for articles published from database inception to July 31, 2020, for studies that included patients who had index allergies to a natural penicillin and were tested for tolerability to cefazolin or that included patients who had index allergies to cefazolin and were tested for tolerability to a natural penicillin. A total of 3228 studies were identified and 2911 were screened for inclusion. Data Extraction and Synthesis: Data were independently extracted by 2 authors. Bayesian meta-analysis was used to estimate the frequency of allergic reactions. Main Outcomes and Measures: Dual allergy to cefazolin and a natural penicillin. Results: Seventy-seven unique studies met the eligibility criteria, yielding 6147 patients. Cefazolin allergy was identified in 44 participants with a history of penicillin allergy, resulting in a dual allergy meta-analytical frequency of 0.7% (95% credible interval [CrI], 0.1%-1.7%; I2 = 74.9%). Such frequency was lower for participants with unconfirmed (0.6%; 95% CrI, 0.1%-1.3%; I2 = 54.3%) than for those with confirmed penicillin allergy (3.0%; 95% CrI, 0.01%-17.0%; I2 = 88.2%). Thirteen studies exclusively assessed surgical patients (n = 3884), among whom 0.7% (95% CrI, 0%-3.3%; I2 = 85.5%) had confirmed allergy to cefazolin. Low heterogeneity was observed for studies of patients with unconfirmed penicillin allergy who had been exposed to perioperative cefazolin (0.1%; 95% CrI, 0.1%-0.3%; I2 = 13.1%). Penicillin allergy was confirmed in 16 participants with a history of cefazolin allergy, resulting in a meta-analytical frequency of 3.7% (95% CrI, 0.03%-13.3%; I2 = 64.4%). The frequency of penicillin allergy was 4.4% (95% CrI, 0%-23.0%; I2 = 75%) for the 8 studies that exclusively assessed surgical patients allergic to cefazolin. Conclusions and Relevance: These findings suggest that most patients with a penicillin allergy history may safely receive cefazolin. The exception is patients with confirmed penicillin allergy in whom additional care is warranted.

Vancomycin Hypersensitivity Reactions Documented in Electronic Health Records.

BACKGROUND: Vancomycin, the most common antimicrobial used in US hospitals, can cause diverse adverse reactions, including hypersensitivity reactions (HSRs). Yet, little is known about vancomycin reactions documented in electronic health records. OBJECTIVE: To describe vancomycin HSR epidemiology from electronic health record allergy data. METHODS: This was a cross-sectional study of patients with 1 or more encounter from 2017 to 2019 and an electronic health record vancomycin drug allergy label (DAL) in 2 US health care systems. We determined prevalence and trends of vancomycin DALs and assessed active DALs by HSR phenotype determined from structured (coded) and unstructured (free-text) data using natural language processing. We investigated demographic associations with documentation of vancomycin red man syndrome (RMS). RESULTS: Among 4,490,618 patients, 14,426 (0.3%) had a vancomycin DAL with 18,761 documented reactions (2,248 [12.0%] free-text). Quarterly mean vancomycin DALs added were 253 ± 12 and deleted were 12 ± 2. Of 18,761 vancomycin HSRs, 7,903 (42.1%) were immediate phenotypes and 3,881 (20.7%) were delayed phenotypes. Common HSRs were rash (32% of HSRs) and RMS (16% of HSRs). Anaphylaxis was coded in 6% cases of HSRs. Drug reaction eosinophilia and systemic symptoms syndrome was the most common coded vancomycin severe cutaneous adverse reaction. RMS documentation was more likely for males (odds ratio, 1.30; 95% CI, 1.17-1.44) and less likely for blacks (odds ratio, 0.59; 95% CI, 0.47-0.75). CONCLUSIONS: Vancomycin causes diverse adverse reactions, including common (eg, RMS) and severe (eg, drug reaction eosinophilia and systemic symptoms syndrome) reactions entered as DAL free-text. Anaphylaxis comprised 6% of documented vancomycin HSRs, although true vancomycin IgE-mediated reactions are exceedingly rare. Improving vancomycin DAL documentation requires more coded entry options, including a coded entry for RMS.

Association of ß-Lactam Allergy Documentation and Prophylactic Antibiotic Use in Surgery: A National Cross-Sectional Study of Hospitalized Patients.

Alternative antibiotics for surgical prophylaxis are associated with increased adverse events and surgical site infection compared to cefazolin. In a sample of perioperative inpatients from 100 hospitals in the United States, cefazolin was 9-fold less likely to be used in patients with a documented ß-lactam allergy whereas clindamycin was 45-fold more likely.

Penicillin Allergy Assessment in Pregnancy: Safety and Impact on Antibiotic Use.

BACKGROUND: Penicillin and other beta-lactam antibiotics are recommended for group B Streptococcus and cesarean section prophylaxis, but approximately 10% of pregnant patients report a penicillin allergy. OBJECTIVE: To assess the safety and impact of penicillin allergy evaluation in pregnant patients. METHODS: In this retrospective study of obstetrician-ordered Allergy/Immunology (AI) electronic consultations (e-consults) from September 20, 2017 through December 31, 2019, we reviewed the electronic health record for e-consult recommendation; patient demographic, obstetric, and allergy histories; and peripartum antibiotic utilization with indication. For patients whose electronic consultation recommended an in-person AI evaluation, testing outcomes were determined, and multivariable logistic regression models were used to compare antibiotic use between patients who did and did not receive an in-person AI evaluation. RESULTS: Of 389 obstetrician-ordered e-consults, 363 (93%) recommended an in-person AI evaluation; of these, 222 (61%) patients received an in-person AI evaluation. Of 220 (99%) patients skin tested, 209 (95%) had their penicillin allergy label safely removed. Compared with patients who did not receive an in-person AI evaluation despite it being recommended (n = 141), patients with in-person AI evaluation (n = 222) had reduced peripartum vancomycin (adjusted odds ratio [aOR], 0.07; 95% CI, 0.01-0.33), clindamycin (aOR, 0.17; 95% CI, 0.08-0.34), and gentamicin (aOR, 0.39; 95% CI, 0.19-0.78) use and increased penicillin (aOR, 18.0; 95% CI, 6.30-51.2) use. The fully AI evaluated patients had increased first-line antibiotic prophylaxis for group B Streptococcus (aOR, 26.9; 95% CI, 6.32-114) and cesarean section (aOR, 1.94; 95% CI, 1.06-3.52). CONCLUSIONS: In a sample of 220 pregnant patients with penicillin allergy histories and in-person AI evaluation, penicillin allergy testing was safe and associated with significantly reduced broad-spectrum antibiotic use and increased first-line beta-lactam antibiotic use.

Development and Validation of a Deep Learning Model for Detection of Allergic Reactions Using Safety Event Reports Across Hospitals.

Importance: Although critical to patient safety, health care-related allergic reactions are challenging to identify and monitor. Objective: To develop a deep learning model to identify allergic reactions in the free-text narrative of hospital safety reports and evaluate its generalizability, efficiency, productivity, and interpretability. Design, Setting, and Participants: This cross-sectional study analyzed hospital safety reports filed between May 2004 and January 2019 at Brigham and Women's Hospital and between April 2006 and June 2018 at Massachusetts General Hospital in Boston. Training and validating a deep learning model involved extracting safety reports using 101 expert-curated keywords from Massachusetts General Hospital (data set I). The model was then evaluated on 3 data sets: reports without keywords (data set II), reports from a different time frame (data set III), and reports from a different hospital (Brigham and Women's Hospital; data set IV). Statistical analyses were performed between March 1, 2019, and July 18, 2020. Main Outcomes and Measures: The area under the receiver operating characteristic curve and area under the precision-recall curve were used on data set I. The precision at top-k was used on data sets II to IV. Results: A total of 299 028 safety reports with 172 854 patients were included. Of these patients, 86 544 were women (50.1%) and the median (interquartile range [IQR]) age was 59.7 (43.8-71.6) years. The deep learning model achieved an area under the receiver operating characteristic curve of 0.979 (95% CI, 0.973-0.985) and an area under the precision-recall curve of 0.809 (95% CI, 0.773-0.845). The model achieved precisions at the top 100 model-identified cases of 0.930 in data set II, 0.960 in data set III, and 0.990 in data set IV. Compared with the keyword-search approach, the deep learning model reduced the number of cases for manual review by 63.8% and identified 24.2% more cases of confirmed allergic reactions. The model highlighted important words (eg, rash, hives, and Benadryl) in prediction and extended the list of expert-curated keywords through an attention layer. Conclusions and Relevance: This study showed that a deep learning model can accurately and efficiently identify allergic reactions using free-text narratives written by a variety of health care professionals. This model could be used to improve allergy care, potentially enabling real-time event surveillance and guidance for medical errors and system improvement.

Penicillin Allergy Evaluation Access: A National Survey.

In a study of 121 hospitals from 38 US states, 44% had access to an allergist for inpatient consultations and 39% had access to inpatient penicillin skin testing, indicating that the majority of US hospitals lack sufficient resources to address inpatient penicillin allergies.

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.

Preoperative penicillin allergy testing in patients undergoing cardiac surgery.

BACKGROUND: Cefazolin is a first-line prophylactic antibiotic used to prevent surgical site infections (SSIs) in cardiac surgery. Patients with a history of penicillin allergy often receive less effective second-line antibiotics, which is associated with an increased SSI risk. OBJECTIVE: To describe the impact of preoperative penicillin allergy evaluation on perioperative cefazolin use in patients undergoing cardiac surgery. METHODS: We performed a retrospective cohort study of patients with a documented penicillin allergy who underwent cardiac surgery at the Massachusetts General Hospital from September 2015 to December 2018. We describe penicillin allergy evaluation assessment and outcomes. We evaluated the association between preoperative penicillin allergy evaluation and first-line perioperative antibiotic use using a multivariable logistic regression model. RESULTS: Of 3802 cardiac surgical patients, 510 (13%) had a documented penicillin allergy; 165 (33%) were referred to allergy and immunology practitioners. Of 160 patients (31%) who underwent penicillin allergy evaluation (ie, penicillin skin testing and, if results were negative, an amoxicillin challenge), 154 (97%) were found not to have a penicillin allergy. Patients who underwent preoperative penicillin allergy evaluation were more likely to receive the first-line perioperative antibiotic (92% vs 38%, P < .001). After adjusting for potential confounders, patients who underwent preoperative penicillin allergy evaluation had higher odds of first-line perioperative antibiotic use (adjusted odds ratio, 26.6; 95% CI, 12.8-55.2). CONCLUSION: Integrating penicillin allergy evaluation into routine preoperative care ensured that almost all evaluated patients undergoing cardiac surgery received first-line antibiotic prophylaxis, a critical component of SSI risk reduction. Further efforts are needed to increase access to preoperative allergy evaluation.

Beta-lactam antibiotic test doses in the emergency department.

BACKGROUND: Facilitating beta-lactam antibiotic use in patients reporting beta-lactam allergies in acute care settings is important to individual patient outcomes and public health; however, few initiatives have targeted the Emergency Department (ED) setting. METHODS: We implemented pathways for patients reporting prior penicillin and/or cephalosporin hypersensitivity as part of a hospital guideline in the ED of a large academic medical center in the United States. We described beta-lactam test doses, pathway compliance, hypersensitivity reactions (HSRs), and allergy record updating associated with ED-administered beta-lactam test doses from October 2016 to June 2018. RESULTS: 310 beta-lactam antibiotic test doses were administered to patients with penicillin and/or cephalosporin allergy histories in the study period (average volume 15/month [standard deviation 4]). Test doses were to cephalosporins (85%), penicillins (12%), and carbapenems (4%). 219 (71%) of test doses were compliant with the pathways. Ten patients (3.2%; 95% CI 1.6%-5.9%) had HSRs; five HSR patients (50%) had beta-lactams administered that were not pathway compliant. The allergy record was updated in 146 (47%) of patients, with improvement over the study period (p < 0.001). CONCLUSIONS: Inpatient approaches to prescribing beta-lactams in patients reporting beta-lactam allergies can be operationalized in the ED. Additional efforts are required to ensure guideline compliance and appropriate allergy documentation.