Cardiovascular disease may be the leading cause of death in the United States, but it doesn't affect every American the same. Studies frequently find CVD disproportionately affects racial and ethnic minorities, fueled in part by quality access care (or lack thereof) and stereotypes. However, a new study attempting to level the health care playing field suggests these disparities are wrong.

The 10-year study analyzed data from more than 1.3 million Kaiser Permanente members between the ages of 30 and 90 years old. Study authors estimated race/ethnicity-specific hazard ratios for coronary heart disease separately, creating four risk categories: no diabetes with no prior coronary heart disease; no diabetes with prior coronary heart disease; diabetes with no prior coronary heart disease; and diabetes with prior coronary heart disease. Researchers found blacks, Latinos, and Asians without any prior history of coronary heart disease had a lower risk of developing coronary heart disease compared to whites, regardless of whether or not they had diabetes.

However, among those with prior heart disease and no diabetes, whites had a slightly lower risk of developing the disease than blacks.

"Racial and ethnic differences in diabetes, cardiovascular-disease risk factors and their outcomes, especially in blacks, are well documented," lead author Dr. Jamal S. Rana, of Kaiser Permanente in Oakland, Calif., said in a statement, "but population health estimates are often confounded by differences in access to high-quality health care,"

It's important to note this study was severely limited: First, the authors did not measure for "racial/ethnic differences in acceptance of offered care due to barriers," such as transportation and financial constraints. A recent infographic from found health care disparities largely exist because minority groups are twice as likely to live in poverty as whites, making it harder to access hospitals and medical specialists.

The study sample also consists only of Kaiser patients with insurance, meaning the results may not apply to those who may be uninsured or seek care elsewhere. Data collected by the Centers for Disease Control and Prevention (CDC) in 2013 found Hispanics and non-Hispanic blacks were more likely to lack health insurance at the time of the CDC's interview than non-Hispanic Asians or non-Hispanic whites.

If the present study makes one thing clear, it's that racial and ethnic disparities surrounding preventable disease, like CVD, could be minimized by providing more affordable care and building clinics in low-income neighborhoods and health education.

"We were able to evaluate ethnic differences in risk of future coronary heart disease within a diverse population, which included not only black, but also large Asian and Latino populations, with uniform access to care in an integrated health care delivery system," Rana said. "The results in our report may reflect, not only access to high quality heart disease care, but also systematic efforts by the health plan to improve risk-factors such as high blood pressure and promote smoking cessation across its member population."

Source: Rana J. Liu J, Moffet H, Jaffe M, Sidney S, Karter A. Ethnic Differences in Risk of Coronary Heart Disease in Large Contemporary Population. American Journal of Preventive Medicine. 2016.