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About This Calculator
HAS-BLED is a scoring system to estimate bleeding risk in patients with atrial fibrillation. Prior to the publication of the HAS-BLED manuscript in 2010,1 an older, more complicated algorithm called HEMORR2HAGES was used.2 HAS-BLED has gained popularity over HEMORR2HAGES due to its simplicity and slightly superior predictive ability.
Definition of Bleeding
The HAS-BLED scoring system calculates the risk of major bleeding, which was defined as intracranial bleeding, bleeding requiring hospitalization, a hemoglobin decrease of more than 2 g/dL, or the need for transfusion secondary to bleeding.
The HAS-BLED manuscript originally included a variety of ambulatory and hospitalized patients with atrial fibrillation.1 This patient population included those taking oral anticoagulants, antiplatelet agents, and no antithrombotic therapy (see below).
A follow-up, validation study was published one year later (Lip 2011),3 which included only patients taking oral anticoagulants (warfarin or ximelagatran). This study is commonly used to validate the major bleeding risk of HAS-BLED, but was actually in a different patient population.
References and Additional Reading
- Pisters R, Lane DA, Nieuwlaat R, et al. A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: the Euro Heart Survey. Chest. 2010;138(5):1093-100. PMID 20299623.
- Gage BF, Yan Y, Milligan PE, et al. Clinical classification schemes for predicting hemorrhage: results from the National Registry of Atrial Fibrillation (NRAF). Am Heart J. 2006;151(3):713-9. PMID 16504638.
- Lip GY, Frison L, Halperin JL, Lane DA. Comparative validation of a novel risk score for predicting bleeding risk in anticoagulated patients with atrial fibrillation: the HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) score. J Am Coll Cardiol. 2011;57(2):173-80. PMID 21111555.