What is the calculation for PREVENT (Patient Risk Evaluation and Ventilation for Early Notification and Treatment)?

PREVENT Calculation: Patient Risk Evaluation and Ventilation for Early Notification and Treatment

The American Heart Association PREVENT (Predicting Risk of CVD EVENTs) equation is a cardiovascular risk prediction tool that incorporates traditional risk factors along with estimated glomerular filtration rate (eGFR) in its base model to provide improved cardiovascular disease risk prediction. 1

Components of the PREVENT Equation

The PREVENT equation includes the following variables in its base model:

• Traditional risk factors:
  • Smoking status
  • Systolic blood pressure
  • Cholesterol levels
  • Antihypertensive or statin medication use
  • Diabetes status
• Estimated glomerular filtration rate (eGFR)

Additional Optional Variables

PREVENT offers enhanced models that include:

1. Urine albumin-to-creatinine ratio (UACR)
2. Hemoglobin A1c
3. Social Deprivation Index (SDI)

Mathematical Structure

The PREVENT equation follows a standard risk prediction model structure:

1. Risk factors are assigned coefficients (β) based on their predictive strength
2. The linear predictor (Y) is calculated as: Y = β₀ + β₁X₁ + β₂X₂ + ... + βₙXₙ
   • Where β₀ is the intercept
   • β₁, β₂, etc. are the coefficients for each risk factor
   • X₁, X₂, etc. represent the presence (1) or absence (0) of each risk factor
3. The predicted probability is calculated as: P = odds/(odds + 1), where odds = e^Y

Key Features of PREVENT

• Sex-specific models (separate equations for males and females)
• Race-free approach (does not include race as a predictor)
• Developed on the age scale
• Adjusted for competing risk of non-CVD death
• Provides prediction for:
  • Total CVD (combined endpoint)
  • Atherosclerotic CVD (specific subtype)
  • Heart failure (specific subtype)

Clinical Significance and Performance

The PREVENT equation demonstrates strong predictive performance:

• Median C-statistics in external validation for CVD: 0.794 for females and 0.757 for males
• Well-calibrated with calibration slopes of 1.03 for females and 0.94 for males 1

Practical Implementation

Adding UACR to the base model significantly improves calibration in patients with marked albuminuria (>300 mg/g), making PREVENT particularly valuable for risk assessment in patients with kidney disease 2, 1.

The American Heart Association PREVENT equation represents an advancement over previous risk prediction tools by incorporating kidney function metrics and offering optional variables to account for social determinants of health, providing a more comprehensive and accurate cardiovascular risk assessment 3.