Pooled Cohort Equations for 10-Year ASCVD Risk
The Pooled Cohort Equations are race- and sex-specific algorithms that estimate 10-year risk for atherosclerotic cardiovascular disease (ASCVD) using six variables: age, total cholesterol, HDL cholesterol, systolic blood pressure (treated or untreated), diabetes status, and current smoking status 1.
Variables Required for Calculation
The equations require the following inputs:
- Age (40-79 years)
- Total cholesterol (mg/dL)
- HDL cholesterol (mg/dL)
- Systolic blood pressure (mm Hg) - must specify if treated or untreated
- Diabetes (yes/no)
- Current smoking (yes/no)
Four Separate Equations by Race and Sex
The Pooled Cohort Equations provide distinct calculations for:
- Non-Hispanic White women
- Non-Hispanic White men
- Non-Hispanic African-American women
- Non-Hispanic African-American men
Each equation uses natural logarithms of the continuous variables and includes interaction terms between age and lipids or age and systolic blood pressure 1.
Calculation Method
The risk calculation follows this algorithmic approach 1:
- Calculate natural log (Ln) of age, total cholesterol, HDL-C, and systolic BP
- Calculate any interaction terms (e.g., Ln[Age] × Ln[Total Cholesterol])
- Multiply each value by its race-sex specific coefficient
- Sum all the coefficient × value products ("Individual Sum")
- Apply the formula: 1 - S₁₀^(e^(Individual Sum - Mean Sum))
Where S₁₀ is the baseline 10-year survival rate specific to each race-sex group.
Clinical Example
For a 55-year-old nonsmoker without diabetes, with total cholesterol 213 mg/dL, HDL cholesterol 50 mg/dL, and untreated systolic BP 120 mm Hg, the predicted 10-year ASCVD risks are 1:
- White women: 2.1%
- African-American women: 3.0%
- White men: 5.3%
- African-American men: 6.1%
Implementation Tools
Downloadable spreadsheets and web-based calculators are available at http://my.americanheart.org/cvriskcalculator and http://www.cardiosource.org/science-and-quality/practice-guidelines-and-quality-standards/2013-prevention-guideline-tools.aspx 1.
Applicable Population
Use these equations for non-Hispanic African Americans and non-Hispanic Whites aged 40-79 years without baseline ASCVD (Class I recommendation, Level of Evidence B) 1.
For other ethnic groups (Hispanic, Asian-American), the White equations may be considered, though this carries weaker evidence (Class IIb recommendation, Level of Evidence C) 1. Data were insufficient to develop race-specific equations for these populations 1.
Important Caveats
The equations predict "hard ASCVD events" defined as: nonfatal myocardial infarction, CHD death, or fatal/nonfatal stroke 1. They do not include heart failure or coronary revascularization as endpoints 1.
Risk probabilities are truncated at 1% minimum and 30% maximum because estimates become statistically unstable at the extremes of the data range 1.
The equations were derived from pooled data from ARIC, Cardiovascular Health Study, CARDIA, and Framingham cohorts, representing modern, geographically diverse US populations 1.
Performance Considerations
While the equations have undergone rigorous internal and external validation 1, some studies suggest they may overestimate risk in certain contemporary populations 2, 3. The equations show moderate to good discrimination (C-statistics 0.70-0.79) but calibration varies by population 3, 4.
Note that newer PREVENT equations (2023) have been developed as an alternative, though the Pooled Cohort Equations remain widely used and guideline-recommended 5, 6, 7.