Safety of anticoagulation therapy in well-informed older patients.

BACKGROUND: In older populations, oral anticoagulation therapy (OAT) is underused by physicians, mainly because of fear of bleeding complications. The aim of this study was to determine the incidence of bleeding complications and associated risk factors in a large heterogeneous group of older patients.
METHODS: Combined retrospective and prospective cohort study conducted in geriatric and internal medicine departments. All patients 80 years or older discharged with the recommendation of OAT were followed up for a mean +/- SD of 28.8 +/- 36.3 months. The rate of bleeding events and the quality of anticoagulation were compared across a wide range of demographic and clinical variables and cognitive and functional status. In addition, we assessed the quality of education given to the patient or caregiver on the use of OAT.
RESULTS: Among 15 387 patients 80 years or older, 323 (2.1%) were discharged with the recommendation of OAT. The rate of major bleedings was 2.4 events per 1000 patient-months. Socioeconomic and cognitive variables and functional impairments were not associated with an increased rate of bleeding. In multivariate analysis, insufficient education on OAT as perceived by the patient or caregiver (odds ratio [OR], 8.83), polypharmacy (OR, 6.14), and international normalized ratio values above the therapeutic range (OR, 1.08) were the only significant predictive factors for bleeding complications.
CONCLUSIONS: The rate of bleeding complications, especially major bleedings, was low in this large group of older patients, many with comorbidities and cognitive and functional impairments. Insufficient OAT education was the major factor that predicted bleeding. Therefore, improving and fostering better methods of OAT education may further reduce bleeding complications.