Prevalence and factors associated with preventable drug-related emergency department visits (DREDp) in elderly patients.

Background: The prevalence of emergency department (ED) visits among the elderly is high and increasing. While emergency services for the elderly involve many factors, drug-related problems (DRPs) that can worsen patient conditions are less frequently discussed. This study investigates the prevalence of preventable drug-related ED visits (DRED_p) and the characteristics of DRPs in elderly ED patients through a comprehensive medication review.

Methods: A cross-sectional study was conducted at a non-trauma ED of a university-affiliated tertiary-care hospital. All adult patients aged 60 years and older who were on medications and visited the ED were included. A clinical pharmacist conducted comprehensive medication reviews for each patient. Patients were classified as experiencing drug-related ED visits (DRED) if their primary reason for the visit was associated with a DRP, as determined by both the physician and pharmacist. DRPs attributed to medication errors were categorized as preventable, while other DRPs were assessed for preventability using modified Schumock and Thornton criteria.

Results: The study involved 351 patients with a mean age of 75.5 years (SD 9.3) and an equal male-to-female ratio of ED visits. The median number of comorbidities was five (IQR 3-6), with about half of the patients taking ten or more medications. The interdisciplinary team classified 43 patients (12.3%) as DRED_p, accounting for 58.1% of the 74 (21.1%) drug-related ED visits. All medication errors categorized as causing harm (level E and higher) occurred within the DRED_p group, constituting approximately half of all DRED_p (22 cases, 51.2%). Approximately two-thirds of drug-related ED visits were associated with adverse drug events (ADEs), predominantly involving antithrombotics, oral hypoglycemic agents, and antineoplastics. Multivariable analysis identified that ED visits involving potentially inappropriate medications (PIMs) according to the STOPP criteria and the presence of multiple comorbidities (six or more concurrent diseases) were significantly associated with DRED_p.

Conclusions: About one in ten elderly patients visited the ED due to preventable DRPs. The majority of DRPs leading to ED visits were ADEs. Both the prescription of PIMs and the presence of multiple comorbidities were significantly associated with DRED_p.