Patient Preference and Capabilities Are at Least as Important as Clinical Contraindications as Barriers to Prescribing Warfarin in Patients with Atrial Fibrillation.

BACKGROUND: Prior studies have assessed either physicians’ general perceptions of barriers to oral anticoagulation or actual barriers in a sample of patients, but they have not both been evaluated within the same study. We evaluated physicians’ general perception of barriers to warfarin use and actual critical barriers to prescribing warfarin in their own patients, using a newly developed instrument.

METHODS: We identified 45 barriers to warfarin use from a literature review, input from clinical experts, and a physician focus group. Barriers were classified into 4 groups: patient medical characteristics (n = 18), health care system factors (n = 8), patient capability (n = 13), and patient preference (n = 6). A sample of US physicians (n = 30) who treat atrial fibrillation (AF) patients completed the instrument. Physicians ranked on a 1–10 scale their reluctance (10 = very reluctant) in general to prescribe warfarin if a specific barrier was present in a patient (perceived barriers). Physicians then indicated critical barriers to prescribing warfarin in their own specific AF patients not receiving warfarin. The most highly ranked perceived barriers and the most prevalent critical barriers to prescribing warfarin were assessed.

RESULTS: Factors considered most strongly to influence physicians’ decision not to prescribe warfarin (mean score±SD) in general were: severe bleeding <3 months ago (9.2±1.3), inability to rely on a patient to adhere to medication instructions in general (8.5±1.3), inability to rely on a patient to adhere to complex warfarin instructions (8.3±2.2), patient unwilling to undergo repeat laboratory testing (8.3±2.1), and risk of fall (8.2±1.8). The most prevalent critical barriers to prescribing warfarin [n (%)] in specific AF patients (n = 24) were: patient unwilling to undergo repeat testing [7 (29%)], inability to rely on the patient to adhere to medication instructions in general [4 (17%)], inability to rely on the patient to adhere to complex warfarin instructions [4 (17%)], difficulty getting to monitoring appointments [4 (17%)], and bleeding episode >3 months ago [4 (17%)].

CONCLUSION: Patient preference and capabilities are at least as important as clinical contraindications as barriers to prescribing warfarin in AF patients.