Assessment of health literacy in patients receiving warfarin anticoagulation therapy and correlation of results with anticoagulant control

Abstract

Background By identifying a patient's level of health literacy (HL) one can help to ensure that any health information is tailored to the correct level and by doing so empower the patient to take responsibility for his/her own health and consequently help improve medicines adherence and healthcare outcomes. The efficacy of oral anticoagulation treatment depends on maximising the length of time within the therapeutic range (TTR). Purpose To assess the HL of patients attending a pharmacist-led warfarin anticoagulation clinic using the Rapid Estimate of Adult Literacy in Medicine (REALM) screening tool. To obtain data on the TTR of each patient who has completed the REALM. To analyse the results of the above and establish whether there is a link between adequate HL and anticoagulation control as measured by TTR. Materials and methods Patients were asked to participate and included if they met the following criteria: aged over 18 years, not visually impaired, no hearing impairment, English as a first language and on warfarin for at least 3 months. Patients were asked a series of questions linked to HL and the REALM screening tool was administered. The level of statistical probability used to determine significance was set at p <0.05. Results 129 patients completed the study with a mean age of 72 years (SD 9.5). The most common indication for warfarin was atrial fibrillation (74.4%). Adequate HL was usual among the patients who completed the study (82.2%). A statistically significant positive correlation was found between TTR and level of education and between REALM and level of education. A statistically significant correlation was also found between REALM and how often the patient read a book. Conclusions This study showed an association between a likely predictor of HL (namely level of education) and TTR. Pharmacists are well positioned to identify at-risk patients and tailor education to their needs.