HAS-BLED score: the nine points and how to add them

The HAS-BLED score adds 1 point for each of nine factors in a person with atrial fibrillation: Hypertension, Abnormal renal function, Abnormal liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly (age over 65), Drugs (antiplatelet or NSAID), and alcohol excess. The total runs from 0 to 9. A 78-year-old with uncontrolled hypertension and nothing else scores 2; a 65-year-old with nothing else scores 0.

Not a medical device. Not a diagnosis or dosing recommendation.

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Atrial fibrillation calculators
Pisters R et al. · 2010
The HAS-BLED formula
Worked examples
HAS-BLED reference table
Frequently asked questions

What is the HAS-BLED score?

HAS-BLED is a bleeding-risk score for people with atrial fibrillation (AF), published by Ron Pisters, Deirdre Lane, Robby Nieuwlaat, Gregory Lip and colleagues in Chest in 2010. It's also written HASBLED or HAS BLED, and sometimes called the Pisters bleeding score.

The 2010 abstract says the authors "aimed to develop a practical risk score to estimate the 1-year risk for major bleeding." The name is an acronym for the factors: "Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile international normalized ratio, Elderly (> 65 years), Drugs/alcohol concomitantly."

This page explains each factor and how the points add up. It doesn't say what a given total means.

The HAS-BLED formula

HAS-BLED = hypertension + abnormal_renal + abnormal_liver
         + stroke + bleeding + labile_inr
         + (age > 65 ? 1 : 0)
         + drugs + alcohol

Exact expression the calculator uses:

HAS-BLED = hypertension + abnormal_renal + abnormal_liver + stroke + bleeding + labile_inr + elderly(age>65) + drugs + alcohol; max 9

Each factor is worth 1 point. Maximum: 9.

The nine factors

Letter	Factor	Input	Points
H	Uncontrolled hypertension	`hypertension`	1
A	Abnormal renal function	`abnormal_renal`	1
A	Abnormal liver function	`abnormal_liver`	1
S	Prior stroke	`stroke`	1
B	Bleeding history or predisposition	`bleeding`	1
L	Labile INR	`labile_inr`	1
E	Elderly: age over 65	`age` (18–120)	1 when over 65
D	Concomitant antiplatelet or NSAID	`drugs`	1
D	Alcohol excess	`alcohol`	1

All factors except age are true/false answers from the caller.

How to calculate HAS-BLED

H. Uncontrolled hypertension: 1 point.
A, A. Abnormal renal function: 1. Abnormal liver function: 1. They're scored separately, so both together give 2.
S. Prior stroke: 1.
B. Bleeding history or predisposition: 1.
L. Labile INR: 1. The caller decides this; Magent doesn't read INR results or time in range.
E. Age over 65: 1. Exactly 65 doesn't score.
D, D. Antiplatelet or NSAID use: 1. Alcohol excess: 1. Again scored separately, so both give 2.
Add. The total is 0 to 9.

Why there are nine points but seven letters

HAS-BLED has seven letters, but two of them cover two factors each. "A" is renal and liver function, scored separately. The second "D" is drugs and alcohol, also scored separately. That's how seven letters give a maximum of 9.

What the calculator returns

Magent's calculator returns the total, the maximum of 9, the age it used and a line for each factor. It doesn't return a risk group.

Worked examples

Examples 1–3 are Magent's own expected values for the calculator. Example 4 follows the formula.

Example 1: age 78 with uncontrolled hypertension

Hypertension → 1.
Age 78 is over 65 → 1.
Everything else → 0.
HAS-BLED = 2 (of 9).

Example 2: age 50, nothing present

Age 50 isn't over 65 → 0.
All eight flags false → 0.
HAS-BLED = 0.

Example 3: age 65, nothing present

Age 65 isn't over 65 → 0.
HAS-BLED = 0.

Example 4: everything present

Hypertension, renal, liver, stroke, bleeding, labile INR → 6.
Age over 65 → 1.
Drugs and alcohol → 2.
HAS-BLED = 9, the maximum.

HAS-BLED reference table

Each row is one of Magent's expected values for the calculator.

Age	Factors present	HAS-BLED
78	Hypertension	2
50	None	0
65	None	0

History of the HAS-BLED score

The score comes from Ron Pisters, Deirdre A. Lane, Robby Nieuwlaat, Cees B. de Vos, Harry J.G.M. Crijns and Gregory Y.H. Lip, 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 (volume 138, issue 5, pages 1093–1100).

The abstract sets out the gap: "no handy quantification tool for assessing this risk exists." The score was built "Based on 3,978 patients in the Euro Heart Survey on AF with complete follow-up," using "all univariate bleeding risk factors in this cohort" in a multivariate analysis "along with historical bleeding risk factors."

The study defined major bleeding as "intracranial, hospitalization, hemoglobin decrease > 2 g/L, and/or transfusion."

The abstract describes the result as "a practical tool to assess the individual bleeding risk of real-world patients with AF."

When it's used

The 2010 study looked at people with atrial fibrillation in the Euro Heart Survey. Magent's record describes HAS-BLED as bleeding-risk arithmetic for AF.

Where it's used

The cohort came from the Euro Heart Survey on AF. The abstract describes its patients as "real-world patients with AF," followed for 1 year.

Who uses it

The abstract frames HAS-BLED as a practical score for estimating an individual's bleeding risk in AF.

Limits of the calculation

It adds nine factors. It doesn't diagnose anything or predict any single person's outcome.
Every factor except age is the caller's call. Magent doesn't define "uncontrolled" hypertension, "abnormal" renal or liver function, or "labile" INR, and it doesn't read lab results.
Age over 65 is strict: 65 doesn't score.
This page doesn't give a cutoff or say what any total means.

Clinical decisions belong to a qualified clinician who knows the patient.

CHADS2 is a stroke-risk score in atrial fibrillation, not a bleeding-risk score.
CHA2DS2-VASc is the later stroke-risk score from Lip and colleagues. Some letters look similar (hypertension, stroke, age), but the two scores measure different things and use different age lines.

Glossary

Atrial fibrillation (AF): an irregular heart rhythm starting in the upper chambers of the heart.
INR: international normalized ratio, a blood-clotting test result.
Labile INR: INR results that swing up and down rather than staying steady.
NSAID: non-steroidal anti-inflammatory drug, such as ibuprofen.
Antiplatelet: a medicine that makes platelets less sticky, such as aspirin.

Common mistakes

Scoring age 65. It has to be over 65.
Scoring renal and liver as one point. They're separate; both give 2.
Scoring drugs and alcohol as one point. They're separate; both give 2.
Thinking the maximum is 7. Seven letters, nine points.
Mixing it up with CHA2DS2-VASc. That's a stroke score with different items and age points.

Source

Pisters R, Lane DA, Nieuwlaat R, de Vos CB, Crijns HJ, Lip GYH. 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):1093-1100. DOI: 10.1378/chest.10-0134

Frequently asked questions

What does HAS-BLED stand for?

Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly (over 65), Drugs/alcohol.

How do you calculate a HAS-BLED score?

Add 1 point for each of the nine factors present. The total is 0 to 9.

What HAS-BLED score is high risk?

This page doesn't give a cutoff. It shows how the total is built, and Magent's calculator returns the number without a risk group.

What is the maximum HAS-BLED score?

Two letters (A and D) each cover two factors.

Does age 65 count in HAS-BLED?

No. The factor is age over 65.