[Determinants of bleeding risk in anticoagulated patients in primary care: A retrospective observational study]

To analyze clinical and therapeutic determinants associated with clinically relevant bleeding in anticoagulated patients followed in primary care.

Population-based retrospective observational study. SITE: Primary care centers of Badalona Serveis Assistencials, from January 1 to December 31, 2024.

Adult patients prescribed vitamin K antagonists or direct oral anticoagulants.

No interventions were performed; routinely recorded clinical data were analyzed.

The primary outcome was clinically relevant bleeding according to International Society on Thrombosis and Haemostasis criteria. Descriptive and comparative analyses and exploratory logistic regression adjusted for age, estimated glomerular filtration rate (eGFR), and extreme polypharmacy were performed in patients with available eGFR. Chronic kidney disease was defined as eGFR<60ml/min/1.73m² persisting for at least 3 months.

A total of 1,377 patients were included; 1,189 (86.8%) had atrial fibrillation. Twenty-nine bleeding events were recorded (2.1%; 95% CI: 1.5-3.0). Patients with bleeding were older (83.9 vs 76.3 years; p<0.001), had lower eGFR (57.6 vs 68.1ml/min/1.73m²; p=0.006), more chronic kidney disease (56.0 vs 32.6%; p=0.014), and more hospital admissions (0.91 vs 0.25; p<0.001). In 986 complete cases, only age remained independently associated (adjusted OR 1.08 per year; 95% CI: 1.02-1.14; p=0.006).

Age was the only factor independently associated with bleeding. The findings are exploratory because of the low number of events and incomplete renal function data.