Differences in attitude, education, and knowledge about oral anticoagulation therapy among patients with atrial fibrillation in Europe: result of a self-assessment patient survey conducted by the European Heart Rhythm Association.

The purpose of this patient survey was to analyse the knowledge about blood thinning medications relative to gender, age, education, and region of residence in patients with atrial fibrillation (AF). A total of 1147 patients with AF [mean age 66 ± 13 years, 529 (45%) women] from eight European countries responded to this survey. Most patients understood that the indication for anticoagulation therapy was to 'thin the blood', but 8.1% responded that the purpose of the medication was to treat the arrhythmia. Patients with college or university grades reported less frequent deviations from their target INR range compared with those without schooling (2.8% vs. 5.1%, P < 0.05). The awareness of anticoagulation-related risk of bleedings was lowest in patients without schooling (38.5%) and highest in those with college and university education (57.0%), P < 0.05. The same pattern was also observed regarding patient's awareness of non-vitamin K antagonist oral anticoagulants (NOACs): 56.5% of the patients with university education and only 20.5% of those without schooling (P < 0.05) knew about NOACs, indicating that information about new anticoagulation therapies remains well below the target. Bleeding events were statistically less frequent in patients on NOACs compared with vitamin K antagonists. The education level and patients' knowledge have a direct influence on the global management of the anticoagulation.

Patients' attitude and knowledge about oral anticoagulation therapy: results of a self-assessment survey in patients with atrial fibrillation conducted by the European Heart Rhythm Association.

The purpose of this European Heart Rhythm Association survey was to assess the attitude, level of education, and knowledge concerning oral anticoagulants (OACs) among patients with atrial fibrillation (AF) taking vitamin K antagonists (VKAs), non-VKA oral anticoagulants (NOACs) or antiplatelets. A total of 1147 patients with AF [mean age 66 ± 13 years, 529 (45%) women] from 8 selected European countries responded to this survey. The overall use of OACs and antiplatelets was 77 and 15.3%, respectively. Of the patients taking OACs, 67% were on VKAs, 33% on NOACs, and 17.9% on a combination of OACs and antiplatelets. Among patients on VKAs, 91% correctly stated the target international normalized ratio (INR) level. The proportion of patients on VKA medication who were aware that monthly INR monitoring was required for this treatment and the proportion of patients on NOAC who knew that renal function monitoring at least annually was mandatory for NOACs was 76 and 21%, respectively. An indirect estimation of compliance indicated that 14.5% of patients temporarily discontinued the treatment, and 26.5% of patients reported having missed at least one dose. The survey shows that there is room for improvement regarding education and adherence of patients taking OACs, particularly regarding monitoring requirements for NOACs.

Pharmacoepidemiological assessment of drug interactions with vitamin K antagonists.

PURPOSE: We present a database of prescription drugs and international normalized ratio (INR) data and the applied methodology for its use to assess drug-drug interactions with vitamin K antagonists (VKAs). We use the putative interaction between VKAs and tramadol as a case study. METHODS: We used a self-controlled case series to estimate the incidence rate ratio (IRR) comparing the rate of INR measurements of ≥4.0 in concomitant tramadol and VKA-exposed periods to VKA-only-exposed periods. Secondary analyses considered specific subgroups, alternative exposure criteria, alternative outcome definitions, and other drugs. RESULTS: We identified 513 VKA users with at least 1 INR measurement ≥4.0 and concomitant tramadol and VKA exposure during the observation period. The overall IRR was 1.80 (95% confidence interval [CI], 1.53-2.10), with a stronger association among users of phenprocoumon compared to warfarin (IRR, 3.37; 95%CI, 2.50-4.53 and IRR, 1.46; 95%CI, 1.20-1.76, respectively). We observed larger IRRs with stricter outcome definitions. Concomitant tramadol and VKA exposure was also associated with an increased rate of low INR measurements (i.e., <1.5; IRR, 1.70; 95%CI, 1.37-2.13). Morphine and, to some extent, oxycodone, penicillin, beta-blockers, and inhaled beta-agonists were associated with high INR. CONCLUSIONS: The approach successfully identified an interaction between tramadol and VKA. However, associations observed for other drugs with no known VKA interaction suggest that the current approach may have too low specificity to be useful as a screening tool, at least for drugs for which time-varying confounding may be present.