Evaluation of Anticoagulation Quality Among Older Adults Receiving Warfarin: A Systematic Review

Background Achieving stable anticoagulation with warfarin remains challenging in older adults, who are particularly vulnerable to both thromboembolic and bleeding complications. Despite continued reliance on warfarin in this population, anticoagulation quality has not been comprehensively synthesized. This systematic review evaluated anticoagulation quality among older adults receiving warfarin, focusing on time in therapeutic range (TTR) and international normalized ratio (INR) distribution patterns. Methods PubMed/MEDLINE and Web of Science were systematically searched from January 2000 to August 2025 to identify studies including adults aged ≥ 60 years receiving warfarin and reporting TTR. This review was registered in PROSPERO (CRD420251270126). Results Twelve studies (2 randomized and 10 observational) were included. Observational studies reported variable and frequently suboptimal anticoagulation control (TTR 42.6–78.6%), whereas pharmacist-led management and genotype-guided dosing improved TTR (93% vs. 31.2% and 70.8% vs. 53.44%, respectively). Conclusions Anticoagulation quality among older adults receiving warfarin remains frequently suboptimal in routine clinical practice. Evidence suggests improved anticoagulation control with structured, individualized management strategies.