Patients Prescribed Warfarin with Poor Time in Therapeutic Range (TTR) Have Different Beliefs about Their Illness and Anticoagulation Therapy Compared to Those with a Good TTR - Early Results from the Switching Study

Medication non-adherence is of increasing concern particularly in management of chronic disease. Lifelong anticoagulation is recommended in patients with atrial fibrillation (AF) and those at risk of recurrent venous thromboembolism (VTE). Anticoagulation control with vitamin-K antagonists (VKAs) is assessed according to TTR, with a TTR>65% indicating good control. Research has shown that patients prescribed VKA with a low TTR ( 75%) and those with poor anticoagulation control (TTR The Switching study comprises a series of studies investigating illness perceptions and medicines beliefs in those prescribed chronic anticoagulation therapy. We report early results from the first sub-study: This sub-study compares patient beliefs in those with TTR 75% prescribed VKA, to determine if illness perceptions and/or medication beliefs are associated with anticoagulation control and adherence with VKA. Patients were identified and recruited from the DAWN® databases of the two anticoagulation clinics within King9s College Hospital (UK). Eligible patients were administered a questionnaire pack comprised of validated instruments; the revised illness perceptions questionnaire (IPQ-R), the beliefs about medicines questionnaire (BMQ) and the anti-clot treatment scale (ACTS), to assess patients beliefs about their illness, their medicines and their anticoagulation related quality of life. Patients with a TTR>75% were mailed the questionnaire packs. Those with TTR To date, 71 patients with TTR>75% and 77 patients with TTR 75% group was 73, with 65% diagnosed with AF and 63% were male. Median age in the TTR 75%, compared to those with TTR 75% group. Our early results demonstrate that AF patients with good INR control have a distinct pattern of beliefs compared to those with poor control. This provides scope for anticoagulation services to target specific beliefs in those with poor anticoagulation control to improve adherence in those requiring long-term anticoagulation in AF. This is of particular importance if this sub-set of patients is likely to be prescribed DOACs where patients are not routinely engaged by services. Disclosures Patel: Bayer plc: Research Funding. Arya: Bayer plc: Research Funding. Auyeung: Bayer PLC: Research Funding.