A great deal of attention has been paid in recent years to the issue of racial and ethnic health disparities. Statistic after statistic reveals that minorities in the United States, particularly African-American and Hispanic populations, are in poorer health on average compared to American whites. Infant mortality, heart disease, diabetes, obesity, cancer and other maladies appear in often shockingly higher rates in minority populations, reflecting differences frequently attributed to socioeconomic factors and access to quality health care. But a new study by University of Chicago Medical Center researchers finds that a major contributor to those disparities might be traced back to what’s in the medicine cabinet.
The National Social Life, Health, and Aging Project (NSHAP) is a research effort launched out of the University of Chicago to study a large sample of older Americans. In 2005 and 2006, more than 3,000 in-home interviews were conducted across the country with people between the ages of 57 and 85 about their social activity, their health, and their medical care. As part of the interview, researchers not only asked the subject what medications they were currently taking, they looked at the drugs with their own eyes, taking a medication inventory “by direct observation.”
That thorough scan allowed Dima Qato, Caleb Alexander, and colleagues to analyze racial and ethnic patterns of medication use with unprecedented high fidelity. Previous studies which used insurance claims or prescriptions written to measure medication usage missed a key human factor, said Alexander, assistant professor of medicine.
“As we all know from own experience, what you are prescribed and what you take are often quite different,” Alexander said. “This data was unique in that it allowed for us to observe, from a nationally representative sample of individuals, the medicines people were actually taking.”
The analysis focused on medications prescribed to people at high risk for cardiovascular disease, a condition that has seen great progress recently in preventive medicine. Those included both the cholesterol-lowering prescription drug class of statins and the well-known over-the-counter drug aspirin, which is recommended to people at risk of heart attack and stroke for its anti-clotting abilities. Before the researchers even got to comparing different races and ethnicities, a disturbing overall trend appeared regarding use of these medicines.
“We found that across the board, regardless of race, there was evidence of under-use of both stains and aspirin,” said Qato, a research associate in the Department of Obstetrics & Gynecology.
Less than half of high-risk cardiovascular patients were actively taking widely available medication for their condition. Only 48 percent of those defined as being at high risk were actively taking stains, and even fewer (41 percent) were taking the cheaper, more easily accessible aspirin.
“It’s one of the remarkable things about prescription drug utilization: there is both widespread under and overuse,” Alexander said. “Many people are on these therapies who may not stand the most to gain from them, and many others are not on medicine or therapies when all of the relevant data suggest they should be.”
Broken down by race and ethnicity, the data revealed the expected disparities. High risk African-Americans were found to be less likely than whites to use statins, while curiously, Hispanics showed no difference. But for use of aspirin, both African-Americans and Hispanics at high cardiovascular risk were found less likely to regularly take the medication compared to high-risk whites.
The researchers then looked for reasons why such disparities might exist. But controlling for the usual suspects thought to explain racial and ethnic health disparities – household income, access to care, insurance coverage, and education – failed to eliminate the statistical medication gap between minority and white populations. That leaves other, less well-studied factors that the authors were unable to directly test, such as access to pharmacies, cultural attitudes and suspicions about health care, or demand for preventive vs. curative medications.
Such questions may be addressed in the second wave of NSHAP interviews, which are currently being conducted to follow up on original subjects and expand the subject pool. Returning to homes that researchers visited in 2005 and 2006, before the passage of Medicare Part D lowered drug costs for older adults, will also bring data about the role of drug price in medication use, Qato suggested. In the meantime, the current paper brings the medicine cabinet into the conversation of how best to address racial and ethnic health disparities.
“I think in addition to expanding pharmacies, there has to be some sort of effort to improve the quality of care received by these populations through expanding primary care services,” Qato said. “The assumption here is not that we want to promote or expand the use of medication, we want to improve equity in use of medications, especially if it relates to health disparities.”
Qato DM, Lindau ST, Conti RM, Schumm LP, & Alexander GC (2010). Racial and ethnic disparities in cardiovascular medication use among older adults in the United States. Pharmacoepidemiology and drug safety, 19 (8), 834-42 PMID: 20681002