Under 65
65 – 74 years (+1)
75 years or older (+2)
No
Yes (+1)
No
Yes (+2)
No
Yes (+1)
Male
Female (+1)
Results
Your Score: 0
function calculateChads() {
var chf = parseInt(document.getElementById("chf").value);
var htn = parseInt(document.getElementById("htn").value);
var age = parseInt(document.getElementById("age").value);
var dm = parseInt(document.getElementById("dm").value);
var stroke = parseInt(document.getElementById("stroke").value);
var vascular = parseInt(document.getElementById("vascular").value);
var sex = parseInt(document.getElementById("sex").value);
var totalScore = chf + htn + age + dm + stroke + vascular + sex;
var riskData = {
0: "0%",
1: "1.3%",
2: "2.2%",
3: "3.2%",
4: "4.0%",
5: "6.7%",
6: "9.8%",
7: "9.6%",
8: "6.7%",
9: "15.2%"
};
var recommendation = "";
var riskText = "Estimated annual stroke risk: " + (riskData[totalScore] || "High Risk");
if (totalScore === 0 && sex === 0) {
recommendation = "Low Risk: Anticoagulation therapy is typically not recommended.";
} else if (totalScore === 1 && sex === 1) {
recommendation = "Low Risk (Female): A score of 1 due solely to sex category carries low risk. Anticoagulation is generally not recommended.";
} else if (totalScore === 1 && sex === 0) {
recommendation = "Intermediate Risk: Oral anticoagulation should be considered based on clinical judgment and patient preference.";
} else {
recommendation = "High Risk: Oral anticoagulation therapy is generally recommended to reduce stroke risk, unless contraindicated.";
}
document.getElementById("final-score").innerText = totalScore;
document.getElementById("risk-level").innerText = riskText;
document.getElementById("treatment-rec").innerHTML = recommendation;
document.getElementById("result-container").style.display = "block";
document.getElementById("result-container").scrollIntoView({ behavior: 'smooth' });
}
Understanding the CHA₂DS₂-VASc Score
The CHA₂DS₂-VASc score is a clinical prediction rule used by healthcare professionals to estimate the risk of stroke in patients with non-valvular atrial fibrillation (AFib). Atrial fibrillation is a common heart rhythm disorder that increases the likelihood of blood clots forming in the heart, which can then travel to the brain and cause a stroke.
What Does the Acronym Stand For?
Each letter in the acronym represents a specific risk factor that contributes to the overall score:
C: Congestive Heart Failure (1 point) – History of heart failure or objective evidence of moderate to severe left ventricular dysfunction.
H: Hypertension (1 point) – High blood pressure, even if it is currently controlled with medication.
A₂: Age (2 points) – Patients aged 75 years or older.
D: Diabetes Mellitus (1 point) – History of Type 1 or Type 2 diabetes.
Sc: Sex Category (1 point) – Female biological sex.
Clinical Importance
Clinicians use this score to decide whether a patient requires oral anticoagulants (blood thinners) like Warfarin, Apixaban, or Rivaroxaban. The goal is to balance the benefit of stroke prevention against the potential risk of bleeding caused by the medication.
Example Calculation
Imagine a 70-year-old female patient with high blood pressure and diabetes. Her score would be calculated as follows:
Age 65-74: +1
Hypertension: +1
Diabetes: +1
Sex (Female): +1
Total Score: 4
With a score of 4, this patient is in the high-risk category, and clinical guidelines generally recommend anticoagulation therapy.
Interpreting the Results
The score ranges from 0 to 9. Higher scores indicate a significantly higher annual risk of stroke. While a score of 0 or 1 (in females) often suggests that the risks of blood thinners outweigh the benefits, a score of 2 or more usually indicates a clear benefit for stroke prevention therapy.
Disclaimer: This calculator is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.