To the Editor:
Hohl and colleagues recently published clinical decision rules (CDRs) that may enable the identification of patients visiting the emergency department (ED) with a high risk of adverse drug events (ADEs) for medication review by a medication specialist. This is the first attempt to propose a resource-efficient, systematic ADE screening tool in the ED patient population, with parsimonious rules that make clinical sense. Nevertheless, these results deserve some comments.
The study exclusively focused on ADEs that were the leading cause of the patient's ED visit. However, an earlier study conducted in the same setting, among elder patients presenting to the ED, demonstrated that there was better recognition of those ADEs related to the patient's chief complaint, compared with recognition of ADEs that were not associated with the chief complaint (91% vs. 32.1%, respectively). These results highlight the importance of taking into account ADEs that are not associated with the chief complaint when working to improve ADE recognition among the ED patients.
Through the application of a few criteria, the ADE rule yielded a sensitivity of 96.7%, but with a specificity that could be regarded as insufficient to fit with the organization of many EDs. These CDRs recommend the medication review by a medication specialist once the patient has at least one comorbid condition, and he or she takes at least three prescription medications, which is a very frequent combination among patients presenting to the ED. This limitation is confirmed by the high number of patients requiring medication review when using the ADE rule (about 4 in 10 patients). A second rule was derived taking into account the resource constraints of smaller centers with less pharmacist and medical consultant availability. Despite this second rule being focused on moderate and severe adverse drug reactions, the proportion of ED patients requiring medication review remained high (about 3 in 10 patients). The medication review in so many patients in real time, at the time of the care, is difficult to implement without establishing a permanent pharmacy presence in the ED, which is not the practice in most EDs. A simple way to limit the number of case reviews may be to build a tool that would specifically identify those ADEs that were not recognized by the emergency physicians and would not make the emergency physicians review the cases where they spontaneously recognized an ADE. Further investigations are needed to address this issue.