Kimberly G. Blumenthal

Rising drug allergy alert overrides in electronic health records: an observational retrospective study of a decade of experience

OBJECTIVE There have been growing concerns about the impact of drug allergy alerts on patient safety and provider alert fatigue. The authors aimed to explore the common drug allergy alerts over the last 10 years and the reasons why providers tend to override these alerts. DESIGN Retrospective observational cross-sectional study (2004-2013). MATERIALS AND METHODS Drug allergy alert data (n = 611,192) were collected from two large academic hospitals in Boston, MA (USA). RESULTS Overall, the authors found an increase in the rate of drug allergy alert overrides, from 83.3% in 2004 to 87.6% in 2013 (P < .001). Alarmingly, alerts for immune mediated and life threatening reactions with definite allergen and prescribed medication matches were overridden 72.8% and 74.1% of the time, respectively. However, providers were less likely to override these alerts compared to possible (cross-sensitivity) or probable (allergen group) matches (P < .001). The most common drug allergy alerts were triggered by allergies to narcotics (48%) and other analgesics (6%), antibiotics (10%), and statins (2%). Only slightly more than one-third of the reactions (34.2%) were potentially immune mediated. Finally, more than half of the overrides reasons pointed to irrelevant alerts (i.e., patient has tolerated the medication before, 50.9%) and providers were significantly more likely to override repeated alerts (89.7%) rather than first time alerts (77.4%, P < .001). DISCUSSION AND CONCLUSIONS These findings underline the urgent need for more efforts to provide more accurate and relevant drug allergy alerts to help reduce alert override rates and improve alert fatigue.

Safety and Outcomes of Test Doses for the Evaluation of Adverse Drug Reactions: A 5-Year Retrospective Review

BACKGROUND Graded challenges are the criterion standard for evaluating adverse drug reactions (ADR). Evidence-based guidelines regarding the optimal number of steps for challenges are lacking. OBJECTIVE To determine the safety and outcomes of 1- or 2-step test doses among patients with ADRs seen by the allergy/immunology consult service and to compare the outcomes of 1- or 2-step test doses with multistep challenges performed during the same time period. METHODS We conducted a retrospective chart review of all 1- or 2-step test doses and multistep challenges at a single academic center between 2008 and 2013. Patient demographics, symptoms of initial ADRs, and outcomes of test doses and multistep challenges were reviewed. ADRs were classified by type and were graded by severity. Outcomes of 1- or 2-step test doses were compared with multistep challenges. RESULTS We identified 456 patients who underwent 497 one- or 2-step test doses (mean age, 51 years; 67.5% female patients). The most common drugs that prompted test doses were β-lactams (62%). The majority of patients (n = 444 [89%]) did not experience any ADRs during test doses. ADRs that occurred during test doses (n = 53 [11%]) were most commonly non-immune-mediated (45%) or IgE-mediated (32%), with grade 1 or 2 severity (100%). Forty-nine percent of ADRs during test doses did not receive any treatment. The ADR rate during multistep challenges (10/82 [12%]) was similar to test doses. CONCLUSION One- or 2-step test doses were safe for evaluation of ADRs. Multistep challenges did not confer added safety. Furthermore, 1- or 2-step test doses did not raise concern for induction of tolerance.

The importance of vancomycin in drug rash with eosinophilia and systemic symptoms (DRESS) syndrome.

Drug rash with eosinophilia and systemic symptoms (DRESS) syndrome characterized by fever, rash, eosinophilia, atypical lymphocytes, and multiorgan involvement has a significant mortality. Inpatient vancomycin use is increasing and appears to be emerging as an important etiology of DRESS syndrome. This study highlights the importance of vancomycin as a cause of DRESS syndrome. We reviewed all cases of DRESS syndrome among inpatients consulted by the Allergy & Immunology service at Massachusetts General Hospital (MGH) from July 2009 through December 2010. We also reviewed the use of inpatient parenteral vancomycin over the past 4 years at MGH. Six patients fulfilled clinical criteria for DRESS syndrome, including rash, fever, eosinophilia, and hepatitis, with five (83%) having vancomycin as the attributable cause. Onset of symptoms varied from 12 days to 4 weeks after start of vancomycin treatment. Systemic findings included atypical lymphocytes, lymphadenopathy, nephritis, hypotension, tachycardia, and pharyngitis. Treatment with corticosteroids was required in three cases. Recurrence of peripheral eosinophilia was a marker of disease relapse. In three of the five patients (60%), elevated human herpesvirus 6 (HHV6) IgG titers correlated with greater systemic involvement and prolonged time to resolution. MGH pharmacy records indicate a progressive increase in the number of patients treated with parenteral vancomycin over the last 4 years. Causative agents for DRESS syndrome in an inpatient setting is likely different from that seen in the general population. With increasing use of vancomycin, we are likely to see more cases of DRESS syndrome caused by vancomycin. Recognition of vancomycin as a common cause of inpatient DRESS syndrome is important.

Tackling inpatient penicillin allergies: Assessing tools for antimicrobial stewardship

Background Reported penicillin allergy rarely reflects penicillin intolerance. Failure to address inpatient penicillin allergies results in more broad‐spectrum antibiotic use, treatment failures, and adverse drug events. Objective We aimed to determine the optimal approach to penicillin allergies among medical inpatients. Methods We evaluated internal medicine inpatients reporting penicillin allergy in 3 periods: (1) standard of care (SOC), (2) penicillin skin testing (ST), and (3) computerized guideline application with decision support (APP). The primary outcome was use of a penicillin or cephalosporin, comparing interventions to SOC using multivariable logistic regression. Results There were 625 patients: SOC, 148; ST, 278; and APP, 199. Of 278 ST patients, 179 (64%) were skin test eligible; 43 (24%) received testing and none were allergic. In the APP period, there were 292 unique Web site views; 112 users (38%) completed clinical decision support. Although ST period patients did not have increased odds of penicillin or cephalosporin use overall (adjusted odds ratio [aOR] 1.3; 95% CI, 0.8‐2.0), we observed significant increased odds of penicillin or cephalosporin use overall in the APP period (aOR, 1.8; 95% CI, 1.1‐2.9) and in a per‐protocol analysis of the skin tested subset (aOR, 5.7; 95% CI, 2.6‐12.5). Conclusions Both APP and ST—when completed—increased the use of penicillin and cephalosporin antibiotics among inpatients reporting penicillin allergy. While the skin tested subset showed an almost 6‐fold impact, the computerized guideline significantly increased penicillin or cephalosporin use overall nearly 2‐fold and was readily implemented.

Drug allergies documented in electronic health records of a large healthcare system.

The prevalence of drug allergies documented in electronic health records (EHRs) of large patient populations is understudied.

Approach to the diagnosis of drug hypersensitivity reactions: similarities and differences between Europe and North America

Abstract Drug hypersensitivity reactions (DHRs) affect an unknown proportion of the general population, and are an important public health problem due to their potential to cause life-threatening anaphylaxis and rare severe cutaneous allergic reactions. DHR evaluations are frequently needed in both ambulatory and hospital settings and have a complex diagnosis that requires a detailed clinical history and other tests that may include in vitro tests and in vivo procedures such as skin tests and drug provocation tests. Although over the years both European and U.S. experts have published statements on general procedures for evaluating DHRs, a substantial discordance in their daily management exists. In this review, we highlight both the differences and the similarities between the European and U.S. perspectives. While a general consensus exists on the importance of skin tests for evaluating DHRs, concordance between Americans and Europeans exists solely regarding their use in immediate reactions and the fact that a confirmation of a presumptive diagnosis by drug provocation tests is often the only reliable way to establish a diagnosis. Finally, great heterogeneity exists in the application of in vitro tests, which require further study to be well validated.

The Impact of Reporting a Prior Penicillin Allergy on the Treatment of Methicillin-Sensitive Staphylococcus aureus Bacteremia.

Background Methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia is a morbid infection with mortality benefit from receipt of parenteral β-lactam therapy. A substantial portion of MSSA bacteremia patients report penicillin allergy, but infrequently have true allergy. Objective To determine the frequency and predictors of optimal and adequate therapy in patients with MSSA bacteremia. Design Retrospective cohort. Participants Adult inpatients with MSSA bacteremia, January 2009 through October 2013. Main Measures The primary measure was a trial of optimal therapy (OT), defined as ≥3 inpatient days or discharge on any first-line agents (nafcillin, oxacillin, cefazolin, or penicillin G, if susceptible). The secondary measure was completion of adequate therapy (AT), defined as ≥10 inpatient days or discharge on an agent appropriate for MSSA bacteremia. Data were electronically gathered with key variables manually validated through chart review. Log-binomial regression models were used to determine the frequency and predictors of outcomes. Key Results Of 456 patients, 346 (76%) received a trial of OT. Patients reporting penicillin allergy (13%) were less likely to receive OT trial than those without penicillin allergy (47% vs. 80%, p <0.001). Adjusting for other factors, penicillin allergy was the largest negative predictor of OT trial (RR 0.64 [0.49, 0.83]). Infectious Disease (ID) consultation was the largest positive predictor of OT trial across all patients (RR 1.34 [1.14, 1.57]). Allergy/Immunology consultation was the single most important predictor of OT trial among patients reporting penicillin allergy (RR 2.33 [1.44, 3.77]). Of 440 patients, 391 (89%) completed AT, with ID consultation the largest positive predictor of the outcome (RR 1.28 [1.15, 1.43]). Conclusions Nearly 25% of patients with MSSA bacteremia did not receive OT trial and about 10% did not receive AT completion. Reported penicillin allergy reduced, and ID consult increased, the likelihood of OT. Allergy evaluation, coupled with ID consultation, may improve outcomes in MSSA bacteremic patients.

Adverse and Hypersensitivity Reactions to Prescription Nonsteroidal Anti-Inflammatory Agents in a Large Health Care System

BACKGROUND Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most frequently used medications in the United States. NSAID use can be limited by adverse drug reactions (ADRs), including hypersensitivity reactions (HSRs). OBJECTIVE We aimed to use electronic health record data to determine the incidence and predictors of HSRs to prescription NSAIDs. METHODS We performed a retrospective cohort study of all adult outpatients in a large health care system prescribed diclofenac, indomethacin, nabumetone, or piroxicam between January 1, 2004, and September 30, 2012. The primary outcome was an ADR or HSR attributed to the prescribed NSAID within 1 year of prescription, determined from a longitudinal allergy database. We used natural language processing to classify known ADRs as either HSRs or side effects. Multivariable logistic regression models were used to identify independent risk factors for NSAID HSRs. RESULTS Of 62,719 patients prescribed NSAIDs, 1,035 (1.7%) had an ADR, of which 189 (18.3%) were HSRs. Multivariable regression analysis identified that patients with prior drug HSR history (odds ratio [OR] 1.8 [95% CI 1.3, 2.5]), female sex (OR 1.8 [95% CI 1.3, 2.4]), autoimmune disease (OR 1.7 [95% CI 1.1, 2.7]), and those prescribed the maximum standing NSAID dose (OR 1.5 [95% CI 1.1, 2.0]) had increased odds of NSAID HSR. CONCLUSIONS NSAID therapeutic use can be limited by ADRs; about 1 in 5 NSAID ADRs is an HSR. Both patient and drug factors contribute to HSR risk and are important to guide patient counseling.

Antibiotics Are the Most Commonly Identified Cause of Perioperative Hypersensitivity Reactions.

BACKGROUND Hypersensitivity reactions (HSRs) during the perioperative period are unpredictable and can be life threatening. Prospective studies for the evaluation of perioperative HSRs are lacking, and data on causative agents vary between different studies. OBJECTIVE The objective of this study was to prospectively determine the success of a comprehensive allergy evaluation plan for patients with HSRs during anesthesia, including identification of a causative agent and outcomes during subsequent anesthesia exposure. METHODS All patients referred for a perioperative HSR between November 2013 and March 2015, from a Boston teaching hospital, were evaluated using a standardized protocol with skin testing (ST) within 6 months of HSR. Comprehensive allergy evaluation included collection of patient information, including characteristics of HSR during anesthesia. We reviewed the results of ST and/or test doses for all potential causative medications Event-related tryptase levels were reviewed when available. RESULTS Over 17 months, 25 patients completed the comprehensive allergy evaluation. Fifty-two percent (13 of 25) were female with a median age of 52 (interquartile range 43-66) years. The most frequently observed HSR systems were cutaneous (68%), cardiovascular (64%), and pulmonary (24%). A culprit drug, defined as a positive ST, was identified in 36% (9 of 25) of patients. The most common agent identified was cefazolin (6 of 9). After our comprehensive evaluation and management plan, 7 (7 of 8, 88%) patients tolerated subsequent anesthesia. CONCLUSIONS Cefazolin was the most commonly identified cause of a perioperative HSR in our study population. Skin testing patients within 6 months of a perioperative HSR may improve the odds of finding a positive result. Tolerance of subsequent anesthesia is generally achieved in patients undergoing our comprehensive evaluation.

The Cost of Penicillin Allergy Evaluation

BACKGROUND Unverified penicillin allergy leads to adverse downstream clinical and economic sequelae. Penicillin allergy evaluation can be used to identify true, IgE-mediated allergy. OBJECTIVE To estimate the cost of penicillin allergy evaluation using time-driven activity-based costing (TDABC). METHODS We implemented TDABC throughout the care pathway for 30 outpatients presenting for penicillin allergy evaluation. The base-case evaluation included penicillin skin testing and a 1-step amoxicillin drug challenge, performed by an allergist. We varied assumptions about the provider type, clinical setting, procedure type, and personnel timing. RESULTS The base-case penicillin allergy evaluation costs