Avaliação da implementação de intervenção educacional para pacientes com inefetividade da anticoagulação oral com Varfarina atendidos em hospital universitário: avaliação da : ensaio clínico controlado

Abstract

Introduction: With the increase in life expectancy, there was an increase of the prevalence of chronic diseases, including atrial fibrillation (AF). Warfarin is an oral anticoagulant, coumarin derivative, widely used for thromboembolism prevention, especially stroke, in people with AF. Despite the benefits, warfarin has a narrow therapeutic range, potential interactions with medication and food, as well as risk of adverse events. The anticoagulation quality assessment with warfarin is performed by the time in therapeutic range (TTR), which is calculated from a historical series of International Normative Ratio (RNI) values, being desirable a percentage ≥60%. The use of warfarin requires intense patient participation in the treatment, and this is a challenge in view of the medical health model still prevalent in Brazil. Aim: To evaluate the effectiveness of an educational intervention directed to patients with ineffective oral anticoagulation with warfarin attended in two anticoagulation clinics (AC) of the Brazil's Public Health System. Method: Controlled clinical trial involving patients on warfarin treated in two anticoagulation clinics located in Brazil. Two groups were allocated to the study, the intervention group at Hospital das Clínicas da UFMG (HC-UFMG) and the control group at Hospital Risoleta Tolentino Neves (HRTN), located in Belo Horizonte, Brasil. Inclusion criteria were: age ≥18 anos, both sexes, outpatient follow-up for at least six months AF diagnoses as indication for warfarin use and TTR <60%. The intervention was composed of four meetings offered over a period of four months. The intervention lasted four months, with the intervention based on Paulo Freire theory, and focused on people with low health literacy. Patients were followed up from April 2019 to August 2020, with patients in the control group receiving usual care offered at the anticoagulation outpatient clinic at HRTN. The primary outcome was TTR, as the secondary outcomes were knowledge about oral anticoagulation, and self-report adherence warfarin therapy. These variables were measured in both groups in the pre- and post-intervention phases. The Rosendaal method was used to calculate TTR, the Oral Anticoagulation Test (OAK) instrument to measure knowledge, and data in the medical records for incorrect warfarin use to measure adherence In the post-intervention phase, the measurements of TTR and adherence occurred immediately after (time zero), as well as at three, six, nine and twelve months after intervention. Results: From the 168 participants, 83 were allocated to the intervention group and 85 to the control group. The mean age was 65±12.6 years and 56.6% were women. There were 115 (68.5%) participants with inadequate health literacy and 101 (60.1%) had non-valvar AF as the indication fororal anticoagulation. no statistically significant association was identified between being exposed to the intervention and the outcomes adherence, and TTR. The participation in the intervention contributed to an increase of about three points in the knowledge score (p<0.001). The results pointed to the contribution of educational intervention to the knowledge of patients on warfarin therapy in the context of the real world, and to the need of improvements in the care of patients on warfarin in Brazil and presented an effective educational strategy to achieve quality of care.