What is the Framingham risk factor?

The Framingham Risk Score: A Cardiovascular Risk Assessment Tool

The Framingham Risk Score (FRS) is a validated risk assessment tool derived from the Framingham Heart Study that estimates an individual's 10-year risk of developing coronary heart disease (CHD) or cardiovascular disease (CVD) based on multiple risk factors. 1

Components of the Framingham Risk Score

The FRS incorporates several key risk factors to calculate a person's risk:

• Age: Points assigned based on age ranges
• Sex: Separate scoring systems for men and women
• Total cholesterol: Measured in mg/dL or mmol/L
• HDL cholesterol: Measured in mg/dL or mmol/L
• Systolic blood pressure: With consideration for treatment status
• Smoking status: Current smoking within the past month
• Diabetes status: Presence or absence of diabetes

Calculation Process

1. Assign points for each risk factor based on sex-specific scoring tables
2. Sum the points to get a total risk score
3. Convert the point total to a 10-year risk percentage using conversion tables

For Men:

• Age points range from -9 (ages 20-34) to +13 (ages 75-79)
• Total cholesterol points vary by age and level (0 to 11 points)
• HDL cholesterol points range from -1 (≥60 mg/dL) to +2 (<40 mg/dL)
• Systolic BP points range from 0 to 6 depending on treatment status
• Smoking adds 0-8 points depending on age
• Point totals correspond to 10-year CHD risk ranging from <1% to >30% 1

For Women:

• Age points range from -7 (ages 20-34) to +16 (ages 75-79)
• Total cholesterol points vary by age and level (0 to 13 points)
• HDL cholesterol points range from -1 (≥60 mg/dL) to +2 (<40 mg/dL)
• Systolic BP points range from 0 to 6 depending on treatment status
• Smoking adds 0-9 points depending on age
• Point totals correspond to 10-year CHD risk ranging from <1% to ≥30% 1

Clinical Application

The FRS helps clinicians:

• Identify high-risk individuals who may benefit from more aggressive preventive interventions
• Guide treatment decisions for lipid-lowering therapy, aspirin use, and other preventive measures
• Communicate risk to patients to motivate lifestyle changes

Risk Categories Based on 10-Year Risk:

• Low risk: <10% 10-year risk
• Intermediate risk: 10-20% 10-year risk
• High risk: >20% 10-year risk or presence of CHD equivalents (diabetes, FRS ≥20%) 1

Treatment Implications

The National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) guidelines use FRS to determine LDL cholesterol goals:

• CHD or CHD risk equivalents (10-year risk >20%): LDL goal <100 mg/dL
• 2+ risk factors (10-year risk <20%): LDL goal <130 mg/dL
• 0-1 risk factor: LDL goal <160 mg/dL 1

Limitations and Considerations

• The FRS was developed primarily in white populations of European descent, though it has been validated in other populations with reasonable performance 1
• May overestimate risk in Hispanic-American and Asian-American populations 1
• May not identify individuals with low short-term but high lifetime risk for CHD, especially in younger adults 2
• Does not account for family history of premature CVD, which is an independent risk factor 1
• Different versions exist for predicting different outcomes (all CHD events vs. hard CHD events vs. stroke) 1

Alternative Risk Scores

Several validated risk scores are available:

• ATP III Risk Assessment Tool for hard CHD events
• European HeartScore Programme for fatal atherosclerotic CVD events
• Reynolds Risk Score for CVD risk estimation in women 1

Clinical Pearls

• The FRS should be calculated in patients with two or more cardiovascular risk factors 1
• For initial assessment, values for total cholesterol and HDL cholesterol should be the average of at least two measurements 1
• The designation "smoker" means cigarette smoking in the past month 1
• Blood pressure values used are those obtained at the time of assessment, regardless of whether the person is taking antihypertensive agents 1
• Patients with diabetes and patients with an FRS of 20% or higher are considered CHD equivalents 1

The FRS remains a cornerstone of cardiovascular risk assessment and guides evidence-based preventive strategies to reduce morbidity and mortality from cardiovascular disease.