CME Information : Prospective Validation of Clinical Criteria to Identify Emergency Department Patients at High Risk for Adverse Drug Events

Objectives: Adverse drug events (ADEs) cause or contribute to one in nine emergency department (ED) presentations in North America and are often misdiagnosed. EDs have insufficient clinical pharmacists to complete medication reviews in all incoming patients, even though pharmacist-led medications reviews have been associated with improved health outcomes. Our objective was to validate clinical decision rules to identify patients presenting with ADEs so they could be prioritized for pharmacist-led medication review. Methods: This multicenter, prospective study was conducted in two tertiary and one community hospital in Canada. We enrolled 1,529 adults presenting to EDs over 12 months. We applied two clinical decision rules and collected baseline variables prior to assessments by clinical pharmacists and physicians. We compared the physician and pharmacist diagnoses with the decision rule results. The primary outcome was a moderate or severe ADE, defined as an unintended and harmful event related to medication use or misuse, which required a change in medical therapy, diagnostic testing, consultation, or admission. An independent committee adjudicated uncertain and discordant cases. We calculated the diagnostic accuracy of both rules. Results: Among 1,529 patients, 184 (12.0%) were diagnosed with an ADE. Rule 1 contained the variables 1) having a preexisting medical condition or having taken antibiotics within 1 week and 2) age > 80 years or having a medication change within 28 days. They had a sensitivity of 91.3% (95% confidence interval [CI] = 86.3%– 95.0%) and a specificity of 37.9% (95% CI = 35.3%–40.6%) for ADEs. Conclusions: Our study validated clinical decision rules that can be applied by clinical pharmacists to limit the number of patients requiring medication review, while identifying the majority of patients presenting with clinically significant ADEs. From the Department of Emergency Medicine (CMH, MEW) and the Department of Pharmaceutical Sciences (KB), University of British Columbia, Vancouver, British Columbia; the Centre for Clinical Epidemiology & Evaluation, Vancouver Coastal Health Research Institute (CMH, MEW), Vancouver, British Columbia; the Emergency Department (CMH) and Clinical Pharmacy Services (SAW), Vancouver General Hospital, Vancouver, British Columbia; the Department of Pharmaceutical Services, The Ottawa Hospital (AZ), Ottawa, Ontario; the Department of Emergency Medicine and of Biomedical and Molecular Sciences, Queen’s University (MLAS), Kingston, Ontario; and the Department of Emergency Medicine, University of Ottawa (JJP), Ottawa, Ontario, Canada. Received December 6, 2017; revision received February 27, 2018; accepted March 1, 2018. This work was presented at the Canadian Association of Emergency Physicians Meeting, Quebec City, Canada, June 2016. This work was supported by grants from the Canadian Medical Protective Association and the Ontario AFP Innovation Fund, both nonprofit organizations. The authors have no potential conflicts to disclose. Author contributions: The study was designed by CMH, JJP, and MLAS; CMH, JJP, and MLAS secured funding to conduct the study; MEW obtained ethics approval; KB, AZ, and MEW collected the data; MEW, KA, and AZ cleaned and MEW analyzed the data; and all authors interpreted study findings. CMH drafted the manuscript, and all authors review the manuscript critically for content. All authors take full responsibility for the manuscript. Supervising Editor: Richard T. Griffey, MD, MPH. Address for correspondence and reprints: Dr. Corinne M. Hohl; e-mail: chohl@mail.ubc. ca. ACADEMIC EMERGENCY MEDICINE 2018;25:1015–1027. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2018 The Authors. Academic Emergency Medicine published by Wiley Periodicals, Inc. on behalf of Society for Academic Emergency Medicine. doi: 10.1111/acem.13407 ISSN 1553-2712 1015 Preventable adverse events related to medical care are a common cause of emergency department (ED) visits and hospitalizations and a leading cause of dealth. Of deaths attributable to medical care, those related to medications are the most common. Prospective studies indicate that adverse drug events (ADEs) cause or contribute to one in nine ED visits, indicating a large burden of disease. With the population aging and medication use expanding, these numbers are expected to continue to rise. Physicians working in EDs and on inpatient units do not recognize a medication-related cause in 20% to 50% of ADEs. Lack of timely recognition, correction, and communication of ADEs may prolong harmful medication use and contributes to the excess morbidity, health services use, and costs associated with these events. In contrast to physicians, clinical pharmacists whose training and professional practice focus on medication management are more likely to recognize medication-related presentations. Pharmacist-led medication review in high-risk patients in the ED has been associated with reduced hospital length of stay among those requiring admission. Clinical pharmacists remain a scarce and expensive resource, making routine medication review in all incoming patients untenable. As a result, the majority of patients presenting to EDs with clinically significant ADEs—recognized or not—are discharged without medication review. Evidence-based criteria can enhance the identification and treatment of patients presenting with ADEs and are needed to ensure that high-risk patients are evaluated by clinical pharmacists to optimize their outcomes and reduce subsequent health services utilization. Our group previously prospectively derived clinical decision rules that allow care providers in EDs to identify incoming patients presenting with ADEs. In the derivation study, the objective was to derive clinical decision rules that were sensitive for the detection of adverse events. This would allow their identification early in a patient’s hospital course so that patients could be referred to a clinical pharmacist for medication review. In the present study, our goal was to validate these rules (Figures 1 and 2) by assessing their diagnostic accuracy in a new cohort of patients. A secondary aim was to evaluate the accuracy of variables collected by nurses, to evaluate whether nurses could apply the rules. Based on derivation, our hypothesis was that at least one rule would maintain a sensitivity of >90% in identifying patients with moderate or severe ADEs.