- Enter the shared inputs once — age, sex, hypertension, prior stroke/TIA, and eGFR/CrCl. These feed both scores where they overlap.
- Add the CHA₂DS₂-VASc-only factors: congestive HF / LV dysfunction, diabetes, and vascular disease.
- Add the HAS-BLED-only factors: abnormal liver function, bleeding history/predisposition, labile INR, drugs (antiplatelets/NSAIDs), and alcohol use.
- Read the two metric cards side by side — CHA₂DS₂-VASc (/9) with approximate annual stroke %, and HAS-BLED (/9) with its bleeding-risk band (≥3 = high).
- The net recommendation synthesises both scores using sex-aware OAC thresholds. The CKD overlay reads your entered eGFR/CrCl and shows the tailored DOAC renal-dosing note.
- To use either score on its own, open the standalone CHA₂DS₂-VASc or HAS-BLED tool.
All computation runs in your browser; no values are stored or transmitted.
When to Use
Use this combined tool when making an anticoagulation decision in non-valvular atrial fibrillation (or atrial flutter). Stroke risk and bleeding risk must be weighed together — and the two scores share several inputs (age, hypertension, prior stroke, renal function). Entering those once and reading both scores side by side avoids re-keying and keeps the net benefit explicit. The CKD overlay adds renally-tailored DOAC dosing for patients with reduced eGFR/CrCl, who carry both elevated stroke and elevated bleeding risk.
Appropriate population
Adults with documented non-valvular AF or atrial flutter in whom an oral-anticoagulation (OAC) decision is being made — including the large CKD subgroup, where the stroke–bleeding trade-off is sharpest and renal dose adjustment is essential.
When NOT to rely on it
Do not apply CHA₂DS₂-VASc to valvular AF — moderate-to-severe mitral stenosis or a mechanical heart valve — where a vitamin-K antagonist is indicated regardless of score. HAS-BLED estimates bleeding risk but is not a reason to withhold OAC: a high score flags modifiable factors to correct, not a contraindication. Neither score determines the agent or dose by itself; DOAC renal thresholds are defined by Cockcroft-Gault CrCl, not indexed eGFR. Always confirm against the current prescribing information.
Pearls & Pitfalls
High bleeding risk is not a stop sign
HAS-BLED ≥3 should trigger correction of modifiable factors (blood-pressure control, stopping NSAIDs/unnecessary antiplatelets, correcting anemia, limiting alcohol, improving INR control) and closer follow-up — not automatic withholding of anticoagulation. When stroke risk is high (CHA₂DS₂-VASc ≥2 men / ≥3 women), net clinical benefit almost always still favours OAC.
Shared inputs, two meanings
Some factors count toward both scores but mean slightly different things. Hypertension: CHA₂DS₂-VASc counts any history of/treated HTN; HAS-BLED counts only uncontrolled HTN (SBP >160 mmHg) — toggle the sub-option. Renal function: a low eGFR/CrCl drives both the HAS-BLED "abnormal renal function" point and the DOAC dosing note. Age: ≥75/65–74 set the VASc age band while age >65 sets the HAS-BLED "elderly" point. Prior stroke/TIA scores +2 in VASc and +1 in HAS-BLED.
Pitfalls
(1) Do not apply to valvular AF / mechanical valves — those need a VKA regardless of score. (2) The female sex point is a risk modifier: a woman whose only point is sex is managed as low-risk. (3) Edoxaban is not recommended when CrCl >95 mL/min (reduced efficacy) — a high CrCl is a contraindication, not a green light. (4) DOAC renal thresholds use Cockcroft-Gault CrCl, not indexed eGFR; in advanced CKD/dialysis, evidence is limited and warfarin's benefit is uncertain with higher bleeding/calciphylaxis risk. (5) Labile INR applies only on warfarin (TTR <60%) — skip it on a DOAC.
Why Use It
An anticoagulation decision is never a single number — it is the balance of thromboembolic benefit against hemorrhagic harm. CHA₂DS₂-VASc reliably identifies the truly low-risk patients who can safely avoid OAC, while HAS-BLED surfaces the modifiable bleeding factors that should be corrected before and during therapy. Because the two scores share inputs (age, hypertension, prior stroke, renal function), evaluating them together — entered once — keeps the trade-off explicit and reduces transcription error. In CKD the trade-off is sharpest: the kidney both clears most DOACs and independently raises stroke and bleeding risk, so coupling the scores with an eGFR/CrCl-driven dosing overlay lets you choose the right agent at the right renal dose rather than treating either score in isolation.
How & Why Use Together
This page runs CHA₂DS₂-VASc and HAS-BLED side by side because an anticoagulation decision is the net of stroke risk and bleeding risk — neither score is actionable alone. Enter the shared variables once (age, hypertension, prior stroke, sex, renal function) and both scores update together; the page then reads the two results against this matrix:
| Stroke risk (CHA₂DS₂-VASc) | Bleeding risk (HAS-BLED) | Net decision |
|---|---|---|
| Low (0 men / 1 woman, sex-only) | Any | No oral anticoagulation; reassess as risk factors accrue. |
| High (≥2 men / ≥3 women) | Low (<3) | Anticoagulate — DOAC preferred over warfarin; dose to renal function. |
| High | High (≥3) | Anticoagulate and correct modifiable bleeding factors (BP control, labile INR, antiplatelets/NSAIDs, alcohol); arrange closer follow-up. A high HAS-BLED is a flag, not a veto. |
HAS-BLED never withholds anticoagulation by itself
Its role is to surface and correct reversible bleeding risks, then anticoagulate the patient whose stroke risk warrants it. Withholding OAC on a high HAS-BLED alone exposes the patient to preventable stroke.
Why the shared eGFR/CrCl drives both
Renal function feeds BOTH scores and the dosing overlay at once: it adds a HAS-BLED point when impaired, shapes stroke-risk management, and sets the apixaban/rivaroxaban/dabigatran/edoxaban renal dose (or favours apixaban/warfarin in advanced CKD). Entering it once keeps the stroke score, the bleeding score, and the chosen DOAC dose internally consistent.
AF Anticoagulation Decision — CHA₂DS₂-VASc + HAS-BLED
Enter the shared inputs once, then the score-specific factors. Both scores compute live and the net recommendation synthesises them with sex-aware OAC thresholds. Add an eGFR or CrCl to drive the HAS-BLED renal point and the CKD-tailored DOAC dosing note.
Shared inputs — count toward both scores
CHA₂DS₂-VASc only
HAS-BLED only
⚕ CHA₂DS₂-VASc: CHF (1), Hypertension (1), Age ≥75 (2)/65–74 (1), Diabetes (1), prior Stroke/TIA/TE (2), Vascular disease (1), Sex category female (1); range 0–9. OAC recommended at ≥2 (men)/≥3 (women), considered at 1 (men)/2 (women), none at 0 (men)/1 (women, sex-only). HAS-BLED: uncontrolled Hypertension, Abnormal renal & liver function (1 each), Stroke, Bleeding, Labile INR, Elderly (>65), Drugs & Alcohol (1 each); range 0–9, ≥3 = high bleeding risk. A high HAS-BLED flags modifiable risk — it is NOT a reason to withhold OAC. DOAC renal thresholds use Cockcroft-Gault CrCl, not indexed eGFR. A decision aid, not a substitute for current labels or clinical judgment. Sources: Lip GYH et al. Chest. 2010;137(2):263–272; Pisters R et al. Chest. 2010;138(5):1093–1100; 2023 ACC/AHA/ACCP/HRS AF Guideline.
Next Steps
Use both scores to support — not replace — a shared anticoagulation decision.
- When the net recommendation favours OAC, prefer a DOAC over warfarin in non-valvular AF unless a mechanical valve or moderate-to-severe mitral stenosis is present.
- If HAS-BLED is ≥3, identify and correct every modifiable factor (BP control, stop NSAIDs/unnecessary antiplatelets, correct anemia, limit alcohol, improve INR control) — do not withhold OAC on HAS-BLED alone when stroke risk is high.
- In CKD, confirm the renal dose against the current label using Cockcroft-Gault CrCl; apixaban is generally preferred in advanced CKD and dialysis.
- Reassess both scores and renal function over time — risk factors accrue and a changing eGFR can move a patient across DOAC dosing thresholds.
- Document the indication, agent, dose, and the stroke/bleeding trade-off discussed with the patient.
Evidence & References
CHA₂DS₂-VASc — scoring
| Risk factor | Points |
|---|---|
| Congestive HF / LV dysfunction | 1 |
| Hypertension | 1 |
| Age ≥75 | 2 |
| Age 65–74 | 1 |
| Diabetes mellitus | 1 |
| Prior Stroke / TIA / thromboembolism | 2 |
| Vascular disease (MI, PAD, aortic plaque) | 1 |
| Sex category female | 1 |
Adjusted annual stroke risk & recommendation
| Score | Approx. adjusted stroke rate / yr | Recommendation |
|---|---|---|
| 0 | ~0.2% | No antithrombotic (men 0 / women sex-only) |
| 1 | ~0.6% | Consider OAC (men); women: no therapy if sex-only |
| 2 | ~2.2% | OAC recommended (men); consider OAC (women) |
| 3 | ~3.2% | OAC recommended |
| 4 | ~4.8% | OAC recommended |
| 5 | ~7.2% | OAC recommended |
| 6 | ~9.7% | OAC recommended |
| 7 | ~11.2% | OAC recommended |
| 8 | ~10.8% | OAC recommended |
| 9 | ~12.2% | OAC recommended |
Adjusted annual stroke rates are approximate, drawn from the validation cohort; absolute rates vary by population. OAC thresholds: recommend at ≥2 (men) / ≥3 (women); consider at 1 (men) / 2 (women).
HAS-BLED — scoring & interpretation
| Letter | Risk factor | Points |
|---|---|---|
| H | Hypertension — uncontrolled, SBP >160 mmHg | 1 |
| A | Abnormal renal function — dialysis, transplant, or SCr >2.26 mg/dL (>200 µmol/L) | 1 |
| A | Abnormal liver function — cirrhosis, bilirubin >2×ULN, or AST/ALT >3×ULN | 1 |
| S | Stroke — prior history | 1 |
| B | Bleeding history or predisposition (anemia, bleeding diathesis) | 1 |
| L | Labile INR — if on warfarin, TTR <60% | 1 |
| E | Elderly — age >65 years | 1 |
| D | Drugs — antiplatelet agents or NSAIDs | 1 |
| D | Alcohol — ≥8 drinks/week | 1 |
| HAS-BLED | Bleeding risk | Approx. major-bleed rate / yr | Action |
|---|---|---|---|
| 0–1 | Low | ~1% / year | Anticoagulate per stroke risk; address any factors present |
| 2 | Intermediate | ~2–3% / year | Anticoagulate with care; correct modifiable factors; consider DOAC over warfarin |
| ≥3 | High | >4% / year | Do NOT withhold anticoagulation; aggressively address all modifiable factors; close follow-up |
DOAC renal dosing in CKD
| Agent | Renal dosing |
|---|---|
| Apixaban | 5 mg BID; reduce to 2.5 mg BID if ≥2 of: age ≥80, weight ≤60 kg, SCr ≥1.5 mg/dL. Preferred in advanced CKD; usable with caution in dialysis (5 mg BID per label; many use 2.5 mg BID). |
| Rivaroxaban | 20 mg daily; 15 mg daily if CrCl 15–50; avoid if CrCl <15. |
| Dabigatran | 150 mg BID; consider 110/75 mg by region if CrCl 30–50; avoid if CrCl <30. |
| Edoxaban | 60 mg daily; 30 mg if CrCl 15–50; NOT recommended if CrCl >95 (reduced efficacy) or <15. |
| Warfarin (INR 2–3) | Use in valvular AF / mechanical valves. In advanced CKD / dialysis, benefit is uncertain and bleeding / calciphylaxis risk is higher — apixaban generally preferred. |
DOAC renal thresholds are defined by Cockcroft-Gault CrCl (mL/min), not indexed eGFR. Always confirm against the current prescribing information.
Evidence & References
CHA₂DS₂-VASc was derived and validated by Lip and colleagues (2010) to refine stroke-risk stratification in non-valvular AF, improving identification of truly low-risk patients over the older CHADS₂. HAS-BLED was derived by Pisters and colleagues (2010) as a user-friendly bleeding-risk score; its primary role is to flag and correct modifiable bleeding factors, not to withhold anticoagulation. The 2023 ACC/AHA/ACCP/HRS AF guideline endorses CHA₂DS₂-VASc as the primary risk-stratification tool. DOAC renal-dosing recommendations follow each agent's regulatory label and supporting trials; apixaban has the strongest evidence base in advanced CKD and dialysis.
- Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJGM. Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the Euro Heart Survey on atrial fibrillation. Chest. 2010;137(2):263–272.
- Pisters R, Lane DA, Nieuwlaat R, de Vos CB, Crijns HJGM, 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.
- Joglar JA, Chung MK, Armbruster AL, et al. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation. Circulation. 2024;149(1):e1–e156.
- Apixaban (Eliquis), rivaroxaban (Xarelto), dabigatran (Pradaxa), edoxaban (Savaysa/Lixiana) — U.S. prescribing information (renal dosing sections).
