Effect of Anticoagulation on Hospitalization Costs After Intracranial Hemorrhage in Atrial Fibrillation: A Registry Study

Abstract

Background and purpose: Intracranial hemorrhage (ICH) is the most feared adverse event with oral anticoagulant therapy in patients with atrial fibrillation. The health economic aspects of resuming oral anticoagulant therapy after ICH are unknown. The aim was to estimate hospitalization costs of thromboembolism and hemorrhage subsequent to ICH in 2 patient groups with atrial fibrillation surviving the first 90 days post ICH: (1) patients resuming warfarin therapy within 90 days post ICH and (2) patients discontinuing therapy.

Methods: Retrospective data from Danish national registries were linked to identify patients with atrial fibrillation who suffered an ICH between January 1, 1997, and April 1, 2011. Study start was 90 days after incident ICH. Mortality was evaluated using the Kaplan-Meier estimate. Occurrence of hospitalization-requiring thromboembolism and hemorrhage was used to estimate hospitalization costs by linkage of International Classification of Diseases, Tenth Revision, codes to Danish Diagnosis-Related Group tariffs. The effect of resuming warfarin therapy on average 3-year hospitalization costs was estimated by regression analysis adjusted for between-group differences in baseline characteristics.

Results: In the inclusion period, 2162 patients had an ICH; 1098 survived the first 90 days and were included for analysis, and of those, 267 resumed warfarin therapy. Therapy resumption reduced the mean 3-year hospitalization cost of hospitalized patients significantly by US$ 1588 (95% confidence interval, -2925 to -251) and was significantly correlated with fewer hospitalization days per hospitalized patient (-4.6 [95% confidence interval, -7.6 to -1.6]). The marginal effect of therapy resumption on hospitalization costs per patient was US$ -407 (95% confidence interval, -815 to 2).

Conclusions: Resuming warfarin therapy within 90 days after ICH in patients with atrial fibrillation is associated with a decrease in average hospitalization costs.

Keywords: anticoagulants; atrial fibrillation; cost and cost analysis; hospitalization; intracranial hemorrhages; survival.