HAS-BLED Score for Major Bleeding Risk
Estimates the 1-year risk for major bleeding in patients with atrial fibrillation (c-statistic: 0.72).
Research authors: Pisters R, Lane DA, Nieuwlaat R, de Vos CB, Crijns HJ, Lip GY.
Details Formula Study characteristics Files & References
Model author
Model ID
Revision date
MeSH terms
  • Anticoagulants
  • Atrial Fibrillation
  • Clinical Prediction Rule
  • Bleeding
  • Model type
    Linear model (Calculation)
    No Formula defined yet
    Condition Formula

    Additional information

    Based on 3,978 patients in the Euro Heart Survey on AF with complete follow-up, all univariate bleeding risk factors in this cohort were used in a multivariate analysis along with historical bleeding risk factors. A new bleeding risk score termed HAS-BLED (Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly (> 65 years), Drugs/alcohol concomitantly) was calculated, incorporating risk factors from the derivation cohort.
    Fifty-three (1.5%) major bleeds occurred during 1-year follow-up. The annual bleeding rate increased with increasing risk factors. The predictive accuracy in the overall population using significant risk factors in the derivation cohort (C statistic 0.72) was consistent when applied in several subgroups. Application of the new bleeding risk score (HAS-BLED) gave similar C statistics except where patients were receiving antiplatelet agents alone or no antithrombotic therapy, with c-statistics of 0.91 and 0.85, respectively.

    Study Population

    Total population size: 3978
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    Females: {{ model.numberOfFemales }}

    Continuous characteristics

    Name Mean SD Unit
    CHADS2 score (bleeding risk factors): systolic blood pressure 137 21 mmHg
    CHADS2 score 1.8 1.2 points
    Age 70 11 years
    Body mass index 27 6 kg/m2

    Categorical characteristics

    Name Subset / Group Nr. of patients
    Age >65 years 1790
    ≤65 years 2188
    Atrial fibrillation type First detected 637
    Paroxysmal 1044
    Persistent/permanent 1714
    Medical history: current smoker Yes 456
    Medical history: hypertension Yes 2267
    Medical history: diabetes mellitus Yes 622
    Medical history: coronary artery disease Yes 1197
    Medical history: heart failure Yes 1018
    Medical history: valvular heart disease Yes 625
    Medical history: COPD Yes 439
    Medical history: thyroid disease Yes 336
    Medical history: stroke/transient ischemic attack Yes 361
    CHADS2 score (bleeding risk factors): prior major bleed Yes 61
    CHADS2 score (bleeding risk factors): malignancy Yes 187
    CHADS2 score (bleeding risk factors): renal failure Yes 184
    CHADS2 score (bleeding risk factors): alcohol use ≥8 U/week Yes 170

    Individual HAS-BLED risk score:

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    Individual HAS-BLED risk score:

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    Outcome stratification

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    Conditional information

    Result interpretation

    The HAS-BLED score estimates the risk of major bleeding for patients on anticoagulation for atrial fibrillation.

    About this model:
    The HAS-BLED bleeding risk score was first described in 2010 and is recommended in European and Canadian guidelines to estimate major bleeding risk. In 2011, the Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA) study group described a new bleeding risk scheme for AF (including five weighted risk factors: anemia, severe renal disease, age ≥ 75 years, previous hemorrhage, and diagnosed hypertension).

    Model performance:
    In a validation study by Roldan et al (2013), the HAS-BLED score showed significantly better prediction accuracy than the ATRIA score (c-statistic 0.68 vs 0.59, respectively; P = 0.035). 
    In a study by Lip et al (2011) including 7,329 patients with AF, the c-index for the HAS-BLED score was found to be 0.67.

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    Calculations alone should never dictate patient care, and are no substitute for professional judgement. See our full disclaimer.

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