Objective: We aimed to evaluate the quality and determinants of vitamin K antagonists (VKA) control among very elderly patients in geriatric settings.
Methods: A national cross-sectional survey was conducted among patients aged ≥80 years who were hospitalized in rehabilitation care or institutionalized in a nursing home and who were treated by VKA. Time in therapeutic range (TTR) was computed according to Rosendaal's method.
Results: A total of 2,633 patients were included. Mean [± standard deviation (SD)] age was 87.2 ± 4.4 years and 72.9 % were women. The main indication for VKA therapy was atrial fibrillation (AF; 71.4 %). Mean (±SD) TTR was 57.9 ± 40.4 %. After backward logistic regression, poorer VKA control (TTR <50 vs. ≥50 %) was associated with being hospitalized in rehabilitation care [odds ratio (OR)(rehab. vs. nursing home) = 1.41; 95 % CI 1.11-1.80], the indication for VKA treatment (OR(prosthetic heart valve vs. AF) = 4.76; 95 % CI 2.83-8.02), a recent VKA prescription (OR(<1 vs. >12 months) = 1.70; 95 % CI 1.08-2.67), the type of VKA (OR(fluindione vs. warfarin) = 1.22; 95 % CI 1.00-1.49), a history of international normalized ratio >4.5 (OR = 1.50; 95 % CI 1.21-1.84), a history of major bleeding (OR = 1.88; 95 % CI 1.00-3.53), antibiotic use (OR = 1.83; 95 % CI 1.24-2.70), and falls (OR(≥2 falls during the past year vs. <2) = 1.26; 95 % CI 1.01-1.56).
Conclusion: Overall, VKA control remains insufficient in very old patients. Poorer VKA control was associated with taking VKA for a prosthetic heart valve, a recent VKA prescription, the use of other VKAs than warfarin, a history of overcoagulation and major bleeding, antibiotic use, and falls.