Impact of a Prescription Support Tool to Improve Adherence to the Guidelines for the Prescription of Oral Antithrombotics: The Combi-AT Randomized Controlled Trial Using Clinical Vignettes

Ensuring the appropriateness of prescriptions of oral antithrombotics (ATs, including antiplatelet and anticoagulant agents) is a crucial safety issue, particularly for patients with multiple chronic conditions. Our main objective was to assess the impact of a prescription support tool, synthesized from international guidelines on oral ATs in adult outpatients, on improving physician adherence to the guidelines for prescription of oral ATs. A web-based, open randomized controlled trial using clinical vignettes was conducted in France from November 2018 to February 2019. General practitioners and cardiologists with outpatient practice were contacted to participate in a web-based survey involving three clinical vignettes illustrating cases of adult outpatients with common neuro-cardiovascular diseases. They were asked to answer four multiple-choice questions related to the number of oral AT(s), drug class, dosage and duration of the prescription. Physicians assigned to the experimental arm had access to the prescription support tool. Physicians assigned to the control arm had no access to the tool. The primary outcome measure was the appropriate prescription of oral ATs (i.e., complied with guidelines in terms of the number, drug class, dosage and duration of prescription). An intent-to-treat analysis was performed using a logistic mixed model with a clinical vignette effect and a physician effect nested in the arm of the trial. Four hundred and forty-one general practitioners and 37 cardiologists were randomized to the experimental (n = 238) and to the control arm (n = 240), respectively. In the experimental arm, 55.0% of the prescriptions were appropriate versus 29.4% in the control arm (Odds Ratio (OR): 3.61 (2.60 to 5.02)). Access to the first prescription support tool synthesizing the use of oral ATs for outpatients significantly improved the rate of appropriate oral AT prescriptions according to the guidelines.