Effect of warfarin education on patient knowledge and anticoagulation control: a randomised controlled trial

Background Patient education is a key component of management in the anticoagulated patient. Aim The aim of this study was to establish whether reiteration of warfarin education in the outpatient setting affects patients’ knowledge of warfarin and anticoagulation control. Methods The study was a randomised prospective trial. Participants newly commenced on warfarin at The Royal Melbourne Hospital were randomised to either standard inpatient education ( n = 19) or to receive an additional comprehensive warfarin education session ( n = 21). The primary outcome was warfarin knowledge as assessed by the Oral Anticoagulation Knowledge ( OAK ) test. Secondary outcomes were time in therapeutic range ( TTR ) and complications. The duration of follow‐up was 6 weeks. Results There were no significant differences between the intervention and control groups in OAK test scores (16.3/20 vs 14.4/20, respectively; p = 0.07), TTR (56.9% vs 59.3%, respectively; p = 0.09) or in the incidence of complications. Conclusion Within the limitations of a single‐centre, underpowered study, we did not detect any significant additional benefit to patient knowledge from further outpatient warfarin education. Current standard inpatient education at our centre compared favourably with other such designed interventions outlined in previous studies. Nevertheless, it is possible that certain subsets of the population may benefit from additional education, such as those with mild cognitive impairment and those from non‐English‐speaking backgrounds; however, a much greater sample size would be required to study these groups.