22 May 2003 15:00 GMT

by Tabitha M. Powledge

The way that clinical trials are designed is often clinically inappropriate for African-Americans, report researchers at Duke University.

The oversight can mean that trials studying the effects of lifestyle or behavior changes on risk factors for major disorders such as cardiovascular disease and cancer often report a discouraging result. In many such studies, African-Americans are less successful at lifestyle changes like losing weight than are other groups. Investigators also have difficulty recruiting and retaining black study participants.

In a paper published in the spring issue of Ethnicity and Disease, Jamy Ard and his colleagues argue that clinical trials that promote behavior modification to prevent cardiovascular disease may challenge the ethnic identity of African Americans. Trial participants are likely to resist behavior change that requires them to stop eating familiar, culturally important foods, for instance. Socioeconomic status can also create barriers to behavior change. People who must work two jobs to support their families have difficulties making time for exercise, and cannot spare money for health club expenses, Ard points out.

The researchers propose a new approach to designing clinical trials involving African Americans. They urge using focus groups to review plans for trials and to suggest changes to trial design. Making sure that African American staff members are part of the research team is also central to building trust, says Ard.

Ard stresses the significance of community groups. Recruitment will be more successful, he says, if newspaper advertisements seeking subjects contain endorsements from community figures such as ministers. Incorporating local churches into the project can help participants adhere to lifestyle changes by providing support, promoting physical activity, and even sponsoring pot-luck meals with more emphasis on fruits and vegetables.

"Cultural differences are potentially a way of improving outcomes, not necessarily barriers," Ard told BioMedNet News. "The more we know, the more we can begin to educate investigators to take advantage of strong values that the community holds high."

Church and other community groups have been involved in recruitment for Action to Control Cardiovascular Risk in Diabetes (ACCORD), reports Jeffrey Probstfield, member of the ACCORD Steering Committee and a cardiologist at the University of Washington in Seattle. The huge new study, which the US National Institutes of Health (NIH) launched in February, will test the best approaches to lowering the risk of heart disease and stroke in adults with type 2 diabetes, a disease especially prevalent among African Americans. ACCORD will eventually enroll 10,000 participants from some 70 clinics in the US and Canada. Even though the study will focus on drug interventions, Probstfield points out that almost every clinic employs a diabetes educator with local roots and special expertise in helping patients to modify their diets and get more exercise.

A community-based strategy is also part of a massive new public health campaign launched by the NIH this month. The campaign will focus on motivating black men to eat nine servings of fruits and vegetables a day to reduce their risk for diet-related diseases that disproportionately affect blacks. According to the National Cancer Institute's Lorelei DiSogra, who heads the campaign, it is a long-term program that will employ many tactics, one of which is church involvement.

The NCI is collaborating with the American Cancer Society to design a stand-alone program for encouraging fruit and vegetable consumption that black churches can implement on their own, says DiSogra. She notes that the church project also fits in nicely with one of the Bush administration's core priorities: encouraging what it calls "faith-based initiatives."

Until recently, lifestyle research has been carried out by mostly white researchers working mostly in white populations, notes Victor Stevens, behavioral psychologist at the Kaiser Permanente Center for Health Research in Portland, Oregon.

"When you move to a different population, some things work and some don't," said Stevens. As an example, he points to a recent pilot trial in which he was involved to test the effects of a culturally adapted weight loss program in African American women. The program reported higher attendance and greater weight loss than conventional programs, he reports.

"You simply have to adjust your program to the people you're working with, especially when you're talking about weight loss," argued Stevens. "You need to adjust not just the food but also ideas about body image and gender roles. A good program has to deal with all that stuff." Stevens notes that few researchers are tackling this topic, and he hopes the Duke paper will encourage others to do the same. "One size," he says, "does not fit all."