Heart disease is the leading killer of Americans, so predicting who is at highest risk of heart attack or stroke is a top priority. After decades of relying on a checklist of risk factors identified in the 1950s, which included factors like high cholesterol, high blood pressure, excessive weight gain and family history of heart trouble, heart experts decided to update the formula for calculating risk in 2013.

The new formula focused less on specific cholesterol targets and instead created an algorithm of the most significant risk factors, each weighted for how much they might contribute to heart issues. The problem, as many doctors quickly pointed out, was that the new formula seemed to loosen the criteria for putting people on medications, especially ones that lower cholesterol. Simply being older, for example, could push a person into higher risk territory that would warrant a statin prescription, even if this person ate a healthy diet, got plenty of exercise and wasn’t overweight or hypertensive. So this raised serious questions about whether everyone who qualified for treatment under the new guidelines actually needed it.

In a new report published in the Journal of the American College of Cardiology, researchers found that the new recommendations, created by the American Heart Association (AHA) and the American College of Cardiology (ACC), overestimates the risk of heart trouble up to five to six times. That means that five to six times as many people may be prescribed drugs like cholesterol-lowering statins who won’t necessarily benefit from them.