Clinical Outcome and Costs Based on the Degree of Vitamin K Antagonist Control for Non-Valvular Atrial Fibrillation

Abstract

Adequate anticoagulation control with vitamin K antagonists (VKAs) in non-valvular atrial fibrillation (NVAF) improves health outcomes. Knowing how the economic burden depends on the degree of anticoagulation control may be relevant for decision makers. This study analyses health outcomes and costs in relation to the degree of control of anticoagulation with VKAs in NVAF in primary care using real-world data. Methods: The present study analyzes health outcomes and costs based on Rosendaal's time in therapeutic range (TTR), considering values of TTR > 70% to indicate adequate control. It was carried out using data from 2018, from the perspective of the health system, with a time horizon of 1 year, in 325 Primary Care Centers in Catalonia, Spain. Results: A total of 42,374 real cases were analyzed, with 46.71% categorized as receiving adequate anticoagulation control. All costs were higher for poor anticoagulation control, resulting in EUR 1811.28 per patient for poor anticoagulation control compared with EUR 1609.25 per patient for adequate anticoagulation control. Adequate TTR control provided a protective effect in admissions due to cranial hemorrhage events (ORadj = 0.75; 95% CI, 0.60-0.94), gastrointestinal bleeding (ORadj = 0.66; 95% CI, 0.54-0.80), and mortality (ORadj = 0.65; 95% CI, 0.60-0.70). Conclusions: Adequate anticoagulation control is associated with a reduction in cranial hemorrhage event admissions, gastrointestinal bleeding admissions, and mortality. The cost arising from patients with adequate control was lower than that for patients with inadequate control. Strategies to improve anticoagulation control could improve health outcomes and costs.