About the Framingham Risk Score
In the US, most doctors assess a person’s risk of heart disease using a risk calculator based on the findings from a large, long-term study conducted in Framingham, Massachusetts. This is referred to as your Framingham risk or your Framingham risk score. The Framingham risk score uses a system that includes age, sex, total and HDL (good) cholesterol, smoking, and blood pressure.
What does the Framingham risk score mean?
Your Framingham risk score is your risk of having a heart attack or dying from heart disease within 10 years.
- Low risk = less than 10% chance
- Intermediate risk = 10% to 20% chance
- High risk = more than 20% chance
Who can use the Framingham risk calculator?
The Framingham risk calculator is intended for men and women who have not already had a heart attack or been diagnosed with heart disease.
In addition, if you have any of the following conditions, the risk score does not apply to you because you are automatically considered at high risk for heart disease:
- Stroke or mini stroke (transient ischemic attack)
- Bypass surgery or balloon angioplasty
- Type 2 diabetes
- Kidney disease
- Abdominal aortic aneurysm – a bulging in the large artery in the stomach wall
- Familial hypercholesterolemia – a genetic predisposition to very high cholesterol
- Peripheral artery disease – fatty plaque in the peripheral arteries, usually in the legs
- Carotid artery disease – fatty plaque in the neck arteries
The risk calculator also does not work if you have very high levels of one or more major risk factors, for example, you smoke more than one pack a day or your blood pressure is severely high.
How accurate is the Framingham risk score?
A major criticism of the Framingham-based risk calculator is that it underestimates risk in women.1 Women rarely fall into the high-risk category despite the fact that heart disease is the number one killer of women.2 One reason is that women generally develop heart disease 10 to 15 years later than men do. Another is that the risk calculator includes HDL (good), LDL (bad), and total cholesterol levels but not triglycerides. Triglycerides are another type of lipid that increases your risk for heart disease. A high triglyceride level seems to confer a higher risk of dying from heart disease in women than in men.3, 4
Because the original Framingham study included only white men and women, there were concerns that the risk calculator may not apply to other races. Since then, studies show it is accurate in African Americans and Hispanic women.5, 6 However, it may overestimate the risk of heart disease in Hispanic men and Native-American women. Risk may also be overestimated for Hawaiians of East Asian ancestry or Japanese Americans, whose risk is approximately two thirds that of the people in the Framingham study.7, 8 The calculator may underestimate risk in men and women from South Asia (India and Pakistan) living in western societies whose risk is double that of white Americans.9
The Framingham Risk Score also underestimates risk in people with the metabolic syndrome, a clustering of heart disease risk factors, most of which are not included in the risk score.1
References
1. Linton MF, Fazio S. A practical approach to risk assessment to prevent coronary artery disease and its complications. Am J Cardiol. Jul 3 2003;92(1A):19i-26i.
2. Ford ES, Giles WH, Mokdad AH. The distribution of 10-Year risk for coronary heart disease among US adults: findings from the National Health and Nutrition Examination Survey III. J Am Coll Cardiol. May 19 2004;43(10):1791-1796.
3. Stensvold I, Tverdal A, Urdal P, Graff-Iversen S. Non-fasting serum triglyceride concentration and mortality from coronary heart disease and any cause in middle aged Norwegian women. BMJ. Nov 20 1993;307(6915):1318-1322.
4. Austin MA, Hokanson JE, Edwards KL. Hypertriglyceridemia as a cardiovascular risk factor. Am J Cardiol. Feb 26 1998;81(4A):7B-12B.
5. D’Agostino RB, Sr., Grundy S, Sullivan LM, Wilson P. Validation of the Framingham coronary heart disease prediction scores: results of a multiple ethnic groups investigation. JAMA. Jul 11 2001;286(2):180-187.
6. Grundy SM, D’Agostino Sr RB, Mosca L, et al. Cardiovascular risk assessment based on US cohort studies: findings from a National Heart, Lung, and Blood institute workshop. Circulation. Jul 24 2001;104(4):491-496.
7. Grundy SM, Pasternak R, Greenland P, Smith S, Jr., Fuster V. Assessment of cardiovascular risk by use of multiple-risk-factor assessment equations: a statement for healthcare professionals from the American Heart Association and the American College of Cardiology. Circulation. Sep 28 1999;100(13):1481-1492.
8. Keys A, Menotti A, Aravanis C, et al. The seven countries study: 2,289 deaths in 15 years. Prev Med. Mar 1984;13(2):141-154.
9. Williams R, Bhopal R, Hunt K. Coronary risk in a British Punjabi population: comparative profile of non-biochemical factors. Int J Epidemiol. Feb 1994;23(1):28-37.
