Agreement among Cardiovascular Disease Risk Calculators
Background—Use of cardiovascular disease (CVD) risk calculators is often recommended by guidelines but research on consistency in risk assessment between calculators is limited.
Method and Results—A search of Pubmed and Google was performed. Five clinicians selected 25 calculators by blinded review. Hypothetical patients were created using seven risk factors (age, gender, smoking, blood pressure, high-density lipoprotein, total cholesterol and diabetes) dichotomized to high and low, generating 27 patients (128 total). These patients were run through each calculator by two clinicians. Risk estimates (and assigned risk categories) were compared among calculators. Selected calculators were from eight countries, used five- or 10-year predictions, and estimated either cardiovascular disease or coronary heart disease. Using three-risk categories (low, medium and high), the 25 calculators categorized each patient into a mean of 2.2 different categories, and 41% of unique patients ended up being assigned across all three-risk categories. Risk category agreement between pairs of calculators was 67%. This did not improve when analysis was limited to just the 10-year CVD calculators. In non-diabetics, the highest calculated risk estimate from a calculator averaged 4.9 times higher (range 1.9 to 13.3) than the lowest calculated risk estimate for the same patient. This did not change meaningfully for diabetics or when the analysis was limited to 10-year CVD calculators.
Conclusions—The decision as to which calculator to use for risk estimation has an important impact on both risk categorization and absolute risk estimates. This has broad implications for guidelines recommending therapies based on specific calculators.
- cardiovascular risk calculator
- risk assessment
- risk prediction
- risk score
- risk factors/global assessment
- cardiovascular disease prevention
- Received December 6, 2012.
- Revision received February 26, 2013.
- Accepted March 15, 2013.