Reference: JAMA Intern Med. 2025 Jun 1;185(6):669-678
Practice Point: Pharmacist-led care transitions in the ED prevent recurrent medication-related adverse events.
EBM Pearl: Number needed to treat (NNT) to prevent 1 adverse outcome is calculated as the reciprocal of the absolute risk difference between intervention and control groups.
Fun Fact: A pharmacist (Henri Nestlé) created condensed milk, which was then used by chocolatier Daniel Peter to develop the first solid milk chocolate in 1875. What a wonderful combination of talents!
But wait, there’s more that pharmacists can do! A trial published in JAMA Intern Med presents evidence that pharmacist-led interventions reduce costs and recurrence after ED visits for medication-related events (MREs). In this study, 345 adults (median age 71 years) with an MRE in France were randomized to a pharmacist-led transition of care program or usual care. MREs included adverse drug events/reactions (mostly not due to medication misuse) and disease-related complications associated with medication nonadherence. Examples of MREs included insulin-associated hypoglycemia, NSAID-related kidney dysfunction, and pulmonary edema related to nonadherence to diuretic therapy.
In this trial, most patients were on 3-10 medications, with around 30% requiring hospitalization. In 96%, there was a direct link between the MRE and the reason for the ED visit. The intervention primarily centered around post-ED follow-up. Usual care consisted of a routine medication history taken by an ED pharmacist and postdischarge letter to the patient’s primary care provider, whereas the pharmacist-led transition of care program added written detailed management recommendations and postdischarge calls to the primary care provider and provided notifications to the community pharmacist. (This communication added about 1 hour to routine ED pharmacist duties.) Patients who received this extra attention were markedly less likely to experience another MRE-related visit to the ED within 6 months for the same reason (3% vs. 22% with usual care).
The EBM statistical concept of “number needed to treat” is calculated as the reciprocal of the absolute risk difference between intervention and control groups (i.e., 22% - 3% = 19% and then 1 ÷ 0.19 = 5.26) and rounded up. Therefore, for every 6 patients with MREs receiving the intervention, we would predict that this intervention would prevent 1 repeat visit in the following 6 months. Future hospitalizations related to the same MRE were also reduced. The study team also quantified cost savings and found that average medical costs related to the MRE were lower with the intervention, equating to a savings of around $1,300.
In general, adverse drug events are usually underreported and unnoticed. This study demonstrates that enlisting the expertise of pharmacists is a valuable tool not only for patient safety but also for identifying potential new safety concerns, which can be written up as case reports or used to generate hypotheses to evaluate associations in case-control or cohort studies.
Think of this kind of intervention as frosting on a chocolate cake — it’s true that a lot of hard work goes into making the cake itself but, as with baking, in health care the finishing touch often makes all the difference!
For more information, see the topic Prevention of Adverse Drug Events in Hospitals in DynaMed.
DynaMed EBM Focus Editorial Team
This EBM Focus was written by McKenzie Ferguson, PharmD, BCPS, Senior Clinical Writer at DynaMed. Edited by Alan Ehrlich, MD, FAAFP, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School; Katharine DeGeorge, MD, MS, Senior Deputy Editor at DynaMed and Associate Professor of Family Medicine at the University of Virginia; Dan Randall, MD, MPH, FACP, Senior Deputy Editor at DynaMed; Gayle Sulik, PhD, Senior Medical Editor and Team Lead for Palliative Care at DynaMed; Rich Lamkin, MPH, MPAS, PA-C, Clinical Writer at DynaMed; Matthew Lavoie, BA, Senior Medical Copyeditor at DynaMed; Hannah Ekeh, MA, Senior Associate Editor II at DynaMed; and Jennifer Wallace, BA, Senior Associate Editor at DynaMed.