Time in the therapeutic range, bleeding event, and their determinants in older patients with atrial fibrillation on warfarin in Ethiopia: multicenter cross-sectional study - Addisu, Zenaw Debasu; Demsie, Desalegn Getnet; Tafere, Chernet; Yazie, Taklo Simeneh; Endeshaw, Destaw; Tefera, Bereket Bahiru; Berihun, Malede; Beyene, Dessale Abate (Frontiers in Pharmacology, 2025)