Health Disparities Research: Progress and Community Impact

In many ways, Kaiser Permanente, with its highly diverse and representative member population, provides an ideal laboratory for studying the sources of disparities and the potential positive or negative impact of a health care system on disparities. Says Andrew J. Karter, PhD, a senior disparities researcher at the Division of Research (DOR): "At least in theory, all Kaiser Permanente members have uniform access to the same relatively high-quality services. So our research can examine potential reasons for observed health disparities that go beyond access and quality issues."

In this way, adds Karter, "research conducted at Kaiser Permanente can complement the large national, population-based studies, which have clearly shown that differences in access to and quality of care are important causes of health disparities."

If access and quality of care are comparable, that leaves a number of other potential explanations for health disparities. These explanations range from differences in social and environmental factors that influence patients' knowledge, beliefs, preferences or self-efficacy, to barriers induced by differential sensitivity to costs, communication barriers between patients and providers or systems of care, cultural differences between providers and patients, and, potentially, discrimination.

Alyce S. Adams, PhD; and Elize Brown, DrPH, JDThese factors can cause de facto differences in access to or quality of health care even within systems such as Kaiser Permanente. In the case of gender and racial/ethnic disparities, biological factors such as genetics must also be considered.

As a national organization, Kaiser Permanente has recognized that understanding and eliminating disparities is a key ethical and fiscal responsibility. "There are few places in this country where you find a large health care system so closely partnered with a large research group toward the common goal of reducing health care disparities," says Alyce S. Adams, PhD, a new investigator at the DOR who is focusing on disparities research. Adams also works closely with Kaiser Permanente's Community Benefit Program in shaping the organization's approach to health disparities.

Gaining a Deeper Perspective on Disparities

Carlos Iribarren, MD, MPH, PhD, and Stephen Sidney, MD, MPHDOR researchers study disparities from a range of perspectives. Often, though not always, they observe a reduction in disparities at Kaiser Permanente relative to the general population. This may suggest that having health insurance enhances access and the quality of health care, which in turn reduces disparities.

In many areas of study, KP researchers find that there are no disparities in the processes of health care, such as rates of mammography or hemoglobin A1c testing. However, some differences in outcomes remain. It is these persisting differences that draw the attention of researchers.

Current disparities research at the DOR includes studies in the areas of diabetes, cancer treatment, asthma, perinatal medicine, coronary artery disease, hypertension, viral hepatitis, and substance abuse. Below are a few examples of compelling findings.

In studying racial and ethnic differences in coronary artery disease, research scientists Carlos Iribarren, MD, MPH, PhD, and Stephen Sidney, MD, MPH, discovered that societal factors, such as lower socioeconomic status rather than race and ethnicity, appeared to explain differences in certain health risks such as recurrence of acute coronary syndrome.

Disparities Research in Diabetes

Meanwhile, TRIAD (Translating Research into Action for Diabetes), a study led by Joe V. Selby, MD, MPH, director of the DOR, surveyed nearly 12,000 patients with diabetes from 10 managed care plans. In that study, both minority race/ethnicity status and lower educational level made independent contributions of comparable size to differences in cardiovascular risk factor control.

Moreover, a host of possible explanatory factors, including communication with and trust in providers, depression, concerns about the costs of medications, and level of physical activity were also related to risk factor control, but they did not appear to explain either the racial/ethnic or socioeconomic differences.

The Diabetes Study of Northern California (DISTANCE) is an ongoing study led by Karter and funded by the National Institute of Diabetes and Digestive and Kidney Diseases that has gathered survey and electronic data from 20,000 Kaiser Permanente Northern California members with diabetes.

DISTANCE is a collaborative study that also involves researchers from several academic centers. It focuses on the role of education and race as two key social indicators in health outcomes. DISTANCE researchers will also study the relationships of neighborhood factors, health literacy, and medication adherence to disparities in diabetes control and complications.

"Thus far, our research shows a pretty steep gradient of worse outcomes associated with lower levels of education, regardless of the complication," says Karter. "But the picture is much less consistent for race and ethnicity. For several major outcomes in diabetes, white patients are at greater risk than any minority population, but for others, particularly renal disease, nonwhite members have higher rates of disease." This complex pattern raises the possibility of biological differences in susceptibility to various complications.

The DOR's Research Program on Genes, Environment and Health (RPGEH) provides a platform for studying biologic as well as environmental and social causes of a broad range of health conditions and, potentially, for understanding observed disparities in those conditions.

Pain management in diabetes is another area in which DOR researchers are focused. Adams, whose previous research has examined disparities in diabetes, will be focusing on disparities in management of pain for patients with diabetes and other chronic pain syndromes. "I hope to find out whether there are differences in how patients report pain, in how that pain affects their lives, and in their patterns for accessing health care services and seeking treatment," she says.

"It's not just looking at the health system but also the patient perspective to understand where the disparities come from. A person's culture may influence how patients describe their pain or their treatment preferences. I will be looking at whether there are disparities in Kaiser Permanente as there have been identified in other settings."

Engaging the Community

The DOR's disparities research is strengthened through growing partnerships with communities to translate research evidence, define barriers to improved outcomes, and develop ideas for effective, sustainable interventions within the community and the health care setting. "The more you partner with diverse groups, the more you learn to identify disparities and understand how they affect people's lives," says Elize Brown, DrPH, JD, director of community research collaborations and acting administrative director at the DOR.

Brown led the formation of a 30-member Community Advisory Panel (CAP) for the RPGEH. Over the past two years, the CAP has met quarterly to provide advice on ethical, legal, and social implications arising from the RPGEH enterprise. "It has been really good to have a broad range of views and experiences around the CAP table. It keeps us humble and accountable and shows us that people beyond our walls do care about the work we do. The CAP also helps build alliances with other organizations in the community."