Atrial fibrillation (AF) is the most preventable cause of stroke. However, despite widely available risk stratification tools, numerous options for oral anticoagulation, and evidence-based practice guidelines, anticoagulation for stroke prevention in AF is consistently under-prescribed. In a pair of observational cohort analyses within the MGB health system, prescription of anticoagulation for stroke prevention in AF was less frequent in ambulatory clinic patients than in those who were hospitalized at the time of assessment (46.9% vs. 57.2%). Implementation science strategies, including computerized decision support (CDS), have been proposed as solutions to improve adherence to guideline recommendations. A previously conducted randomized controlled trial of alert-based CDS in 458 high-risk hospitalized patients with AF who were not being anticoagulated showed that the alert nearly tripled the proportion of hospitalized patients with AF and high-risk of stroke who were prescribed anticoagulation during the hospitalization, at discharge, and at 90 days compared with the control group. CDS in this trial was associated with an 88% reduction in the frequency of stroke or systemic embolic event and 87% reduction in the frequency of myocardial infarction (MI) at 90 days. A subsequent trial demonstrated that clinician-directed, alert-based CDS doubled prescription of antithrombotic therapy in high-risk ambulatory care patients with AF who were not prescribed anticoagulation at the time of randomization. A major lesson from the second trial was the importance that perceived bleeding risk played in the shared decision-making process between clinician and patient. These two trials demonstrated that bleeding risk is the predominant consideration when omitting anticoagulation or choosing to bypass a CDS alert. Clinicians often overestimate bleeding risk compared with objective bleeding risk scores (HAS-BLED).
Both prior trials were executed at a large tertiary-care center in Boston, Massachusetts. The feasibility and impact of an alert-based CDS strategy to improve stroke prevention in AF among ambulatory care patients in the community setting and outside of major tertiary-care centers remains to be determined. To address the feasibility and impact of a CDS strategy in the non-tertiary care, community medical center setting, this study will involve a multicenter, community-based, cluster-randomized controlled trial of a more sophisticated CDS focused not only on implementation stroke prevention but also on bleeding risk assessment and management.
