Physician’s Weekly talked with Peter J. Zed, BSc, BSc (Pharm), ACPR, PharmD, FCSHP, and Neil J. MacKinnon, PhD, FCSHP, about their recent study that found that about one of every 12 emergency department (ED) visits by pediatric patients is medication related.
PW: What makes medication-related pediatric ED visits an important topic to study?
PZ: Adverse drug events and patient safety in healthcare have come to the forefront in the last decade. Much of the work on adverse drug events and patient safety has been conducted in adults and pediatric patients are often under-represented or excluded from this work. As a result, there are gaps in the literature surrounding the understanding of the impact of adverse drug events in pediatric patients.
NM: To date, no prospective trials have been conducted in this area. In the United States, we’re trying to reduce preventable hospital readmissions, and we know that many medication-related issues are preventable. ED visits can result in hospital admission, so tackling the issue of preventable hospital admissions from the ED is important.
PW: Tell us about your recent study published in Pediatrics. What was the purpose of this research?
PZ: We wanted to understand the frequency, severity, preventability, and types of adverse events that occur in pediatric patients that are significant enough to bring them to the ED. We only considered the ED visit as medication-related if it was directly related to the use or misuse of their medications.
NM: The goal of our study was to determine how many ED visits in pediatric patients are medication related, and then further divide those visits into severity level and preventability. Also, we wanted to see if length of stay was different between admitted and non-admitted patients.
PW: What are the most important findings from your study?
PZ: Of kids who presented to the ED, 8% had an adverse drug-related event, of which 65% were preventable. We predicted before starting the study that the rate would be around 4%. These events are far more common than what most people probably appreciate. Some of the surprises from our findings included the rate of admission and the length of stay for patients who had an event. For patients who did not present with a medication-related visit (MRV), the rate of admission was about 5%; however for those who presented with a MRV, the rate of admission was 27%, and the median length of hospital stay was 1.5 days longer than for patients who did not present with a MRV. These events have a significant impact on the healthcare system, including implications on resource utilization in hospitals.
NM: About one in every 12 ED visits for pediatric patients appeared to be medication-related. This number adds up quickly when you consider all the ED visits that occur among children. The vast majority were either moderate or severe adverse drug events that could truly have an impact on patient outcomes. The categorizing of these events was also interesting. The most frequent category was adverse drug reactions, which probably is the least surprising. But the next two highest were sub-therapeutic dose and non-adherence to therapy. If you combine these two categories, it re-emphasizes the importance of ongoing medication management.
PW: What are the key takeaways from your findings on the classification, preventability, and severity of medication-related ED visits?
PZ: When most people think of medication-related events, they usually think of adverse drug reactions such as upset stomach, diarrhea, or rashes. These are issues that can be caused from medication use. However, adverse drug reactions only comprised about 26% of all events in our study. I think one of the key takeaways is that there are many different types of adverse drug-related events in pediatric patients. A second key point is that the preventability rate was exceedingly high but consistent with previous work in adult patients.
NM: When comparing preventable versus not preventable events, the adverse drug reactions were primarily not preventable. For any given drug, a certain percentage of patients are going to experience adverse consequences that are largely unpreventable. However, 100% of the non-adherence events and almost all of the sub-therapeutic doses were deemed preventable. If something is preventable in healthcare, it means that we’re not optimizing outcomes and improvement is necessary.
PW: What factors were associated most frequently with medication-related ED visits in your study population (Table)?
PZ: Previous studies have shown that a number of factors are consistently associated with medication-related events in adults, including patient age, the number of medications a patient receives, and the number of comorbidities they have. The theory is that as people age, they may have more illnesses or more diseases that need to be treated. As a result, patients are on more medications. By that factor, they are ultimately at greater risk for experiencing an adverse drug event. This trend emerged in our study, but it was a secondary analysis that requires further exploration.
NM: There were many different factors, but the only one that can be deemed “preventable” was the number of prescribers. The odds ratio for a medication-related ED visit for a child with more than one prescriber was 1.52. Emergency providers should pay special attention to children who have more than one prescriber.
PW: How should emergency physicians incorporate your findings into their daily practice?
PZ: Emergency physicians should be aware that adverse drug events are a common cause of pediatric patients presenting to the ED. A thorough evaluation of that association between the medication use, misuse, non-adherence, or other factors should be a component of every patient assessment. This recognition must be made by physicians as well as nurses, pharmacists, and other emergency medicine providers. In addition, many patients go home from the ED with prescription medications. When writing that prescription, providers should consider what could happen to patients when they get home and explain to them when follow-up is necessary. They should also put measures in place to help minimize potential adverse drug events, such as working with family or community providers.
NM: Any time a physician sees an older adult, the first thing they should think about is whether the office visit was due to a side effect of a drug or an adverse reaction. Usually when patients present to physicians, clinicians look at whether they have a new disease or a flare up of an existing disease go through a diagnostic flow chart, and then think about medications. Our study shows that when a child presents with symptoms in a physician’s office or the ED, drugs need to be at the top of the “suspect list” for issues like side effects, adverse reactions, non-adherence, and sub-therapeutic doses. Non-adherence could result from the medication tasting poorly, the pill being too big for the child to swallow, or issues of affordability. Physicians can look at the issues we identified and should keep them top of mind when seeing pediatric patients who present to the ED.
What do you see as being important areas of future research focused on this topic?
PZ: Studies consistently show that 50% to 70% of adverse drug events are preventable. Future work needs to focus on the targeted interventions and approaches to care that can be implemented to minimize these events and ultimately improve outcomes and the economic impact these events have on our system.
NM: Now that we’ve identified the problem, the next step is to determine how to most effectively address it. Interventions that reduce preventable adverse drug events in pediatrics would be the next area of research to examine. We should further explore strategies that are the most effective and cost-effective. For example, better software in an electronic health record system could be more proactive at identifying at-risk patients. Increasing staffing of clinical pharmacists in the ED may also be of benefit.
Zed P, Black K, Fitpatrick E, et al. Medication-related emergency department visits in pediatrics: a prospective observational study. Pediatrics. 2015;135:435-443. Available at
Zed P, Haughn C, Black K, et al.. Medication-related emergency department visits in pediatrics: a qualitative systematic review. J Pediatrics. 2013;163:477-483.
Zed P, Abu-Laban R, Balen R, et al. Incidence, severity and preventability of medication-related visits to the emergency department: a prospective study. CMAJ. 2008;178:1563-1569.
Budnitz D, Pollock D, Weidenbach K, et al. National surveillance of emergency department visits for outpatient adverse drug events. JAMA. 2006;296:1858-1866.
Hafner J, Belknap S, Squillante M, Bucheit K. Adverse drug events in emergency department patients. Ann Emerg Med. 2002;39:258-267.