Universal coverage may narrow gaps in health outcomes

3 min read

Health care disparities in the United States have long been noted, with particular attention paid to the gaps separating racial and economic groups. And while some research has looked at how insurance — and lack of insurance — contributes to this imbalance, few, if any, studies have quantified the impact of universal coverage on differences in health outcomes between these groups.

Now, by analyzing measures of blood pressure, cholesterol, and blood sugar collected between 1999 and 2006 from the National Health and Nutrition Examination Survey (NHANES), a team of researchers in the Harvard Medical School (HMS) Department of Health Care Policy has compared the health outcomes of individuals by race, ethnicity, and education. What’s more, the researchers studied whether overall discrepancies between these demographic groups were narrowed among adults with Medicare coverage after age 65. 

Looking at data for more than 6,000 individuals between the ages of 40 and 85, researchers probed important indicators of disease control for hypertension, diabetes, and coronary heart disease. They found that while health indicators improved for all groups between 1999 and 2006, the socio-demographic gaps remained unchanged or, in some cases, widened. However, among individuals ages 65 and older who were eligible for Medicare, a federal social insurance program, the gaps narrowed substantially.

These findings are reported in the April 21 issue of the Annals of Internal Medicine. The study was funded by The Commonwealth Fund, a private foundation supporting independent research on health policy reform and a high performance health system.

“The tide is rising and it is lifting all boats, but many are still left behind,” says lead author J. Michael McWilliams, HMS assistant professor of health care policy medicine and an associate physician in the Division of General Medicine at Brigham and Women’s Hospital. “In addition to quality improvement efforts, we will likely need universal coverage to achieve good control for all adults with these conditions.”

The researchers noted that controlling blood pressure, cholesterol, and blood sugar are critical steps to prevent devastating complications of cardiovascular disease and diabetes, such as heart attacks, strokes, kidney disease, and premature death. These disease control measures were provided by NHANES, a research program of the National Center for Health Statistics, where clinicians travel to all regions of the United States to examine and provide on-the-spot health evaluations for individuals.  All data from this program are publicly available.

The researchers discovered a number of examples where racial, ethnic, and socioeconomic gaps closed once individuals were eligible for Medicare. For example:

•    For systolic blood pressure, racial disparities decreased by 60 percent.

•    For blood sugar levels with diabetes, educational disparities decreased by 83 percent, while racial and ethnic disparities fell by 78 percent.

•    For total cholesterol levels, educational disparities disappeared altogether.

“We found some important indicators that universal health insurance may reduce persistent disparities we’ve seen for far too long in Americans from different racial or ethnic groups,” says senior author John Ayanian, professor of health care policy and medicine at Harvard Medical School, HMS professor of medicine at Brigham and Women’s Hospital, and professor of health policy and management at the Harvard School of Public Health.

“The results of this study make it clear that guaranteeing access to affordable insurance for all Americans is the essential first step toward a high performing health care system and a healthier America,” said Commonwealth Fund President Karen Davis. “As our leaders look toward health reform it is critical that they take into account the value of health care coverage for everyone and assure that all Americans have the ability to obtain insurance for themselves and their families.”