Different CV risk calculators are inconsistent in classifying risk for the same patients
The use of risk calculators is increasingly common, but many calculators still use data gathered in older, homogeneous populations that predate the modern era of statins, aspirin, and antihypertensives. This article serves as a warning that we need to carefully choose which calculator to use with which population, and we need to make sure that the calculators are regularly updated and appropriately calibrated. (LOE = 2c)
|Study Design: Cross-sectional||Funding: Government|
|Setting: Population-based||Allocation: Unknown|
Practice guidelines are increasingly based on cardiovascular risk factors, because overall risk is critical for determining how much a patient will benefit from a preventive medication such as aspirin or a statin. These authors identified 25 such calculators, and created 128 imaginary patients, each with a different combination of 7 cardiovascular risk factors (diabetes mellitus, age, sex, tobacco use, blood pressure, and HDL and total cholesterol levels). They determined whether each risk calculator placed each patient in a low-, moderate- or high-risk category. They then compared each calculator with each other calculator and determined the percentage of times that the calculators’ results agreed with one another. For example, if the calculators both placed 20 patients in the low-risk group, 22 patients in the moderate-risk group, and 22 patients in the high-risk group, but disagreed about the other 64 patients, they would have 50% agreement. Agreement varied, with the average agreement generally in the 60% to 70% range (mean = 67%). The Progetto Cuore score (average agreement = 46%) and 2 scores based on the United States National Cholesterol Education Program guidelines (55.4% and 56.2% agreement) were noticeably worse. For 41% of the 128 imaginary patients, at least one calculator put them in the low-, moderate-, and high-risk groups. Only 28% of patients were assigned to the same risk group by all 25 calculators.
Mark H. Ebell, MD, MS
University of Georgia