Clinical calculator
CHADS2 Score
A browser-only educational calculator for the classic CHADS2 atrial fibrillation stroke-risk score. Information entered on this page is not saved or stored by RPHprep.
RPHprep provides educational exam-preparation content only. It is not medical advice, legal advice, or a substitute for professional judgment. Users should consult current Canadian laws, standards, guidelines, product monographs, and official regulatory resources.
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Only digits 0 to 9 and a single decimal point are acceptable as numeric inputs. This calculator uses checkbox inputs only.
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CHADS2 score inputs
Stroke risk per 100 person-years
| Score | On warfarin Rx | No warfarin Rx |
|---|---|---|
| 0 points | 0.25 | 0.49 |
| 1 points | 0.72 | 1.52 |
| 2 points | 1.27 | 2.50 |
| 3 points | 2.20 | 5.27 |
| 4 points | 2.35 | 6.02 |
| 5 to 6 points | 4.60 | 6.88 |
References
- Gage BF, Waterman AD, Shannon W, et al. Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation. JAMA. 2001;285(22):2864-2870. PubMed
- Go AS, Hylek EM, Chang Y, et al. Anticoagulation therapy for stroke prevention in atrial fibrillation: how well do randomized trials translate into clinical practice? JAMA. 2003;290(20):2685-2692. PubMed
- Cairns JA. CHA2DS2-VASc had better discrimination than CHADS2 for predicting risk for thromboembolism in atrial fibrillation. Ann Intern Med. 2011;154(10):JC5-13. PubMed
- Olesen JB, Lip GY, Hansen ML, et al. Validation of risk stratification schemes for predicting stroke and thromboembolism in patients with atrial fibrillation: nationwide cohort study. BMJ. 2011;342:d124. PubMed
- Wild D. CHADS2 score predicted bleeding and death in atrial fibrillation treated with anticoagulants. Ann Intern Med. 2012;156(8):JC4-13. PubMed
- Oldgren J, Alings M, Darius H, et al. Risks for stroke, bleeding, and death in patients with atrial fibrillation receiving dabigatran or warfarin in relation to the CHADS2 score: a subgroup analysis of the RE-LY trial. Ann Intern Med. 2011;155(10):660-667. PubMed