ACC 2016: Patients routinely overestimate risk of cardiovascular disease

April 2, 2016 – Only 27 percent of patients estimated their risk within 10 points of their calculated risk.

Patients are often unable to correctly assess their risk for cardiovascular disease, according to a new study presented Saturday at the annual Scientific Sessions of the American College of Cardiology in Chicago.

To identify potential candidates for statin therapy to prevent cardiovascular disease, current guidelines recommend that clinicians first calculate a patient’s 10-year risk of heart attack or stroke. Then, clinicians should discuss that risk with the patient as part of a broader conversation about cardiovascular disease prevention.

“We focus on using 10-year risk to identify treatment candidates, but we don’t know a lot about how patients understand their own risk of heart disease to begin with,” said the DCRI’s Ann Marie Navar, MD, the study’s lead author.

In this study, Navar and her colleagues surveyed 2,856 U.S. patients aged 40 years and older without cardiovascular disease to estimate their 10-year risk, and compared these with calculated risks using the calculator recommended by the current 2013 ACC/AHA Guidelines.

The researchers found no correlation between patients’ estimates of their risk and calculated CVD risk estimates. Only 27.3 percent of patients estimated their risk within 10 points of their calculated risk, and most people overestimated their risk of heart disease.

“We were surprised by this, because other studies have shown high rates of ‘optimistic bias,’ where people think they are healthier than they really are,” Navar said.

Women and younger adults tended to overestimate their risk, while men and older adults, on average, underestimated their risk. Education level was not linked to the magnitude of overestimation. People on statins overestimated their risk slightly more than those who were not on statins.

Given that most individuals overestimate their risk, the researchers noted the possible unintended consequences of interventions that focus on communicating 10-year risk to patients.

“What happens when you tell someone who thinks they have an 80 percent chance of heart attack or stroke in the next 10 years that it’s only 10 percent?” Navar said. “We need to better understand how what we tell patients about risk affects their behavior.”

In addition to Navar, the study’s Duke authors included Tracy Wang, MD, MHS, MSc; Michael Pencina, PhD, and Eric Peterson, MD, MPH.