SNAP AF-52: Dose Appropriateness and Adherence to Oral Anticoagulation in Adults ≥65 With Atrial Fibrillation in Primary Care (Ordu, Türkiye)

SNAP AF-52 is an ambidirectional observational registry conducted in family health centers (primary care) across Ordu, Türkiye, enrolling adults ≥65 years with a pre-existing diagnosis of atrial fibrillation. The study assesses (a) label-concordant dosing of oral anticoagulants (DOACs/warfarin) using drug-specific criteria, and (b) medication adherence via Proportion of Days Covered (PDC) over the prior 12 months (good adherence defined as PDC ≥80%). Unsafe findings (e.g., suspected under-/overdosing, critical drug-drug interactions, very low renal function) trigger same-day referral to tertiary cardiology for evaluation and management. The retrospective window is Dec 1, 2024-Nov 30, 2025; the prospective single-visit inclusion window is Dec 1, 2025-May 31, 2026. No experimental treatment is administered; all care is routine.