Researchers used real-world clinical data to attempt to emulate a randomized controlled trial testing the effectiveness of two blood thinners, apixaban and warfarin, to prevent stroke in patients with non-valvular atrial fibrillation. The study, led by Emma Maud Powell at the London School of Hygiene and Tropical Medicine, UK, and publishing August 29 th in the open-access journal PLOS Medicine , provides a method to explore the effects of treatments in patients who are underrepresented or excluded from clinical trials. Patients experiencing atrial fibrillation – a potentially dangerous medical condition in which the upper chambers of the heart beat irregularly – will often be prescribed blood thinners such as apixaban or warfarin to prevent a stroke.
However, these treatment recommendations are based on results from randomized controlled trials, and it is unknown if they are applicable to populations of patients who were not included in the trial or present only in very low numbers. In the new study, researchers used routinely collected health data from patients in the United Kingdom to attempt to emulate a previous randomized controlled trial that compared the effectiveness of apixaban and warfarin. They attempted to emulate the patient eligibility, selection and analysis approaches as the previous trial.
They found that patients prescribed apixaban had similar outcomes to patients prescribed warfarin, but unlike the previous trial, they did not find that apixaban was s.