Frequency and Risk Factors for Under- and Over-Treatment in Stroke Prevention for Patients with Non-Valvular Atrial Fibrillation in General Practice

OBJECTIVE: To determine adequacy of antithrombotic treatment in patients with non-valvular atrial fibrillation. To determine risk factors for under- and over-treatment. DESIGN: Retrospective, cross-sectional study of electronic health records from 36 general practitioners in 2008. SETTING: General practice in the Netherlands. SUBJECTS: Primary care physicians (n = 36) and patients (n = 981) aged 65 years and over. MAIN OUTCOME MEASURES: Rates of adequate, under and over-treatment, risk factors for under and over-treatment. RESULTS: Of the 981 included patients with a mean of age 78, 18% received no antithrombotic treatment (under-treatment), 13% received antiplatelet drugs and 69% received oral anticoagulation (OAC). Further, 43% of the included patients were treated adequately, 26% were under-treated, and 31% were over-treated. Patients with a previous ischaemic stroke were at high risk for under-treatment (OR 2.4, CI 1.6-3.5), whereas those with contraindications for OAC were at high risk for over-treatment (OR 37.0, CI 18.1-79.9). Age over 75 (OR 0.2, CI: 0.1-0.3]), diabetes (OR 0.1, CI: 0.1-0.3), heart failure (OR 0.2, CI: 0.1-0.3), hypertension (OR 0.1, CI: 0.1-0.2) and previous ischaemic stroke (OR 0.04, CI: 0.02-0.11) protected against over-treatment. CONCLUSIONS: In general practice, CHADS2-criteria are being used, but the antithrombotic treatment of patients with atrial fibrillation frequently deviates from guidelines on this topic. Patients with previous stroke are at high risk of not being prescribed OAC. Contraindications for OAC, however, seem to be frequently overlooked.