VPB0033 - Prevention of stroke and other thromboembolic events in primary care: alarming data from a Brazilian medium-size city

Background: Despite the development and increasingly common use of direct oral anticoagulants, warfarin is still widely used in clinical practice, mostly in low and middle income countries. Health literacy, patient knowledge regarding oral anticoagulation treatment, and medication adherence are essential to achieve the desired therapeutic effect of warfarin, despite their scarce information in clinical practice.

Aims: Evaluate the profile of patients using warfarin, followed up in primary care.

Methods: Consecutive adult (>=18 years-old) on oral anticoagulation with warfarin being monitored at 27 primary care units in Divinópolis (MG) were recruited between November/2018 and February/2020. Clinical information was collected from medical records, and patients were invited to perform the following tests: Oral Anticoagulant Knowledge test; adaptation of the Treatment Adherence Measure (MAT) to oral anticoagulation; Short Assessment of Health Literacy for Portuguese-speaking Adults (SAHLPA-18) and Pharmacotherapy Complexity Index.

Results: Throughout, 162 patients were included (mean age 65 ± 12 years-old, 55.6% women). The main indications for anticoagulation were non-valvular atrial fibrillation/flutter (26.5%) and venous thromboembolism (24.1%). In 13.6% of patients, the reason for anticoagulation treatment was not recorded. The MAT-adapted indicated that 83.3% of the patients were adherent to the treatment. The OAK showed only 11.7% of patients with an adequate level of knowledge about anticoagulant therapy. According to the SAHLPA-18, 67.9% of patients have inadequate health literacy. In the review of medical records, there was lack of essential clinical information, such as INR results and conduct.

Conclusion(s): This study reveals an alarming scenario in the primary care setting, considering the short therapeutic window of warfarin, its pharmacological complexity, and its food and drugs interactions. Additionally, it was noticed a failure in the public health system, regarding lack of essential information about anticoagulant therapy.
Thefore, these results highlighted the insufficient knowledge about warfarin therapy and the poor health literacy of the population assisted by primary care.