An Electronic Medical Record Intervention to Increase Pharmacologic Prophylaxis for Venous Thromboembolism in Emergency Department Observation Patients

Study objective: The role of venous thromboembolism (VTE) prophylaxis among patients receiving emergency department (ED) observation unit care is unclear. We investigated an electronic health record-based clinical decision support tool aimed at increasing pharmacologic VTE prophylaxis use among at-risk patients placed in ED observation units. Methods: We conducted an interrupted time-series study of an Epic-based best practice advisory implemented in May 2019 at a health care system comprising 2 academic medical centers and 4 community hospitals with dedicated ED observation units. The best practice advisory alerted staff at 24 hours to conduct a risk assessment and linked to a VTE prophylaxis order set. We used an interrupted time series, Bayesian structured time series, and a multivariable mixed-effect regression model to estimate the intervention effect. Results: Prior to the best practice advisory implementation, there were 8,895 ED observation unit patients with a length of stay more than or equal to 24 hours, and 0.9% received pharmacologic VTE prophylaxis. Afterward, there were 12,664 ED observation unit patients with a length of stay more than or equal to 24 hours, and 4.8% received pharmacologic VTE prophylaxis. The interrupted time series and causal impact analysis showed a statistically significant increase in VTE prophylaxis (eg, absolute percent difference 3.8%, 95% confidence interval 3.5 to 4.1). In a multivariable model, only the intervention was significantly associated with receiving VTE prophylaxis (odds ratio 4.56, 95% confidence interval 2.22 to 9.37). Conclusion: An electronic health record-based alert helped to prompt staff caring for ED observation unit patients at risk for VTE with prolonged visits to order recommended pharmacologic prophylaxis. The best risk assessment model to use and the true incidence of VTE events in this population are unclear. [Ann Emerg Med. 2024;83:24-34.]