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February 19, 2009

RESEARCH NOTES

Distrust impacts blacks’ participation in research

Distrust toward medicine and research plays a significant role in African-Americans’ lack of participation in clinical trials, according to a study by researchers at Children’s Hospital and the Graduate School of Public Health (GSPH) that appears in the February issue of Archives of Pediatrics & Adolescent Medicine.

The researchers found that children’s enrollment in clinical research studies depends on parental attitudes, beliefs and expectations.

In a research survey of 140 African-American and 50 white parents of Children’s Hospital patients, African-American parents were twice as likely to be distrusting of medical research as white parents.

Education level also was associated with distrust, with high distrust scores among 74 percent of those with less than a high school education vs. 44 percent of college graduates. However, race remained associated with higher levels of distrust even after the researchers controlled for education, with African-American parents being two times more likely to distrust compared with white parents.

This study was conducted by Children’s Hospital pediatrician and School of Medicine pediatrics professor Kumaravel Rajakumar in collaboration with Stephen Thomas, the Philip Hallen Professor of Community Health and Social Justice and director of the Center for Minority Health at GSPH.

Rajakumar said, “Parental distrust toward medicine and research can be a barrier for enrollment of children in clinical research studies. The higher levels of distrust among African-American parents can mean that they are less likely to enroll their children in clinical trials, which can have profound implications for eliminating racial and ethnic health disparities, as it impacts the extent to which research findings can be applied to the general population including minorities.

“Our study also found that financial and other incentives would only be moderately effective in increasing participation. As a medical community, we need to develop better strategies for overcoming the distrust of African-American parents to help achieve adequate participation of African-American children in clinical research.”

Thomas said, “Race matters. It is important for the biomedical research community to acknowledge that African-American distrust toward medicine and research is not irrational; on the contrary, it reflects the legitimate discontent of far too many black families who experience racial discrimination when seeking medical care, along with the clear and convincing evidence of racial disparities in their health status compared with whites’. The experience of discrimination is not limited to one individual or one generation but is passed on through word of mouth, keeping alive the cultural memory of how medical science was used to justify the racial inferiority of African Americans.”

The authors concluded that the use of culturally appropriate recruitment materials and using research assistants with similar racial and cultural backgrounds as the subject population can help provide accurate information and quell parental distrust toward clinical research.

Additionally, the establishment of community research advisory boards, which provide feedback at all stages of a research study, as has been done in Pittsburgh, is another means to ensure that minority community members participate and disseminate information about studies while protecting the interests of research subjects and potentially reducing distrust.

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DNA testing may reveal little about disease risks

Scientists may be a long way off from using genetics to reliably gauge risks for specific diseases, say GSPH researchers in a study published Feb. 5 in the online journal PLoS Genetics. Yet, many companies currently offer personalized genetic testing for diseases like cancer, heart disease and diabetes, and tout the ability of DNA testing to predict future health risks. 

Daniel E. Weeks, senior author and professor of human genetics and biostatistics at GSPH, said: “The rapid discovery of new genetic risk factors is giving us vitally important insights into human health, but a strong association between these factors and disease risk may not reliably predict which health issues a specific individual will face in the future. Our study indicates that even though we can paint a picture of our genetic makeup with current tests, this may not be enough to help us understand our individual risk for disease.”

The study focused on single nucleotide polymorphisms, or SNPs — variations in short DNA sequences that have been linked to the presence of particular diseases, and that exist in the millions in the human genome. A number of companies currently offer individualized estimates for disease risks based on genome-wide SNP genotyping. These tests typically scan 500,000 to 1 million SNPs, searching for only a handful associated with a specific disease. 

Weeks and colleagues focused their study on age-related macular degeneration, type 2 diabetes, prostate cancer, cardiovascular disease and Crohn’s disease — conditions for which there are strongly associated genetic variants. They found that a strong genetic association did not guarantee they could accurately discriminate between actual disease cases and controls in both mathematical models and real-world examples.

Part of the problem may be a statistical one. To provide meaningful insights, a test for disease risk needs to identify positive cases accurately and provide a low false positive rate. One of the challenges with current approaches to genetic testing is that they are based on a very small number of common variants, “making it likely that you will identify people as high risk who may not be at risk at all,” said Weeks. “With such a small pool of variants, it’s difficult to develop a very meaningful test for predicting disease risk.” 

In addition, he said, few health care providers have adequate genetics training to make sense of the risk calculations now commercially offered and to advise their patients accordingly.

Weeks suggests the need for longitudinal studies to define true risk and to understand how genetic susceptibility may interact with known environmental and lifestyle risk factors.

“With more study, our hope is that genetic testing will benefit people and encourage positive lifestyle changes and guide clinical decisions. In the meantime, we need to take a step back and proceed with caution and allow the insights gained from these new association findings to be used to explore the basic biological causes of disease,” he said.  

Pitt co-authors were Yvette Conley, faculty member in the School of Nursing, Robert E. Ferrell, faculty member in GSPH, and Johanna Jakobsdottir, graduate student in biostatistics and human genetics.

The study was supported by the National Eye Institute at the National Institutes of Health, The Steinbach Foundation, Research to Prevent Blindness, the Eye and Ear Foundation of Pittsburgh, the American Health Assistance Foundation and the Jules Stein Eye Institute. 

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“Doughnut hole” gap impacts seniors’ Rx use

Medicare Part D enrollees who reached a gap in health care coverage known as the “doughnut hole” were much less likely to use prescription drugs than those with an employer-based plan, according to a GSPH study. The findings, published in the Feb. 3 online issue of Health Affairs, raise concerns about health consequences and increased costs from hospitalizations and physician visits that may arise from lack of coverage.

To protect seniors, the authors suggest a change in policy that would mandate the coverage of generic drugs in the “doughnut hole” through a modest increase in initial prescription co-pays.

Medicare Part D, which offers prescription drug coverage for Medicare beneficiaries, took effect in January 2006. A controversial aspect of its design is the “doughnut hole,” a gap in coverage of prescription drugs that in 2006 occurred when annual individual drug expenditures reached $2,250. The purpose of the annual spending cap is to keep the cost of the program within federally approved limits.

GSPH health economics professor Yuting Zhang and colleagues compared two groups of senior citizens with Medicare drug coverage provided by a large Pennsylvania insurer in 2006. One group was covered through more generous employer-sponsored plans with full coverage in the “doughnut hole.” The other was covered through Medicare Advantage prescription drug plans (MA-PD) with no “doughnut hole” drug coverage or generic coverage only.

They found that one in four MA-PD enrollees reached the “doughnut hole,” but only one in 20 of that subset went on to reach the catastrophic phase of coverage — when annual drug spending reached $5,100 and Part D coverage of drugs resumed.

In addition, Medicare beneficiaries who lacked coverage in the “doughnut hole” reduced their monthly prescriptions by 14 percent per month once they entered the “doughnut hole.” Those with generic coverage in the “doughnut hole” decreased their monthly prescriptions by only 3 percent, and those who were enrolled in employer-based plans had no changes in monthly prescriptions when they reached the “doughnut hole” spending level.

The researchers also found that Medicare beneficiaries with diabetes were more likely to reach the “doughnut hole” than those with hypertension, and they reached it sooner. Those with more than one chronic illness also were much more likely to reach the “doughnut hole” — 34 percent with both hypertension and diabetes reached it, and 61 percent of those with hypertension, hyperlipidemia, congestive heart failure and diabetes did so.

“Our findings raise concerns about whether people with chronic illnesses who lack ‘doughnut hole’ coverage are able to effectively manage their conditions,” said Zhang. “Without needed prescriptions, we could potentially see an increase in hospital and physician costs.”

To fill the gap, the researchers suggest mandating generic drug coverage in the “doughnut hole” and offsetting government costs by allowing plans to assess larger co-pays on prescription drugs prior to entering the “doughnut hole.”

Increasing the current initial 25 percent co-pay by 6-9 percentage points, they suggest, would finance generic drug coverage in the “doughnut hole” with up to a $10 co-pay for each monthly prescription, thus providing needed protection to seniors who would otherwise face a gap in coverage.

Pitt co-authors of the study were Judith Lave and Julie Donohue of the Department of Health Policy and Management.

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GSPH research funded

Two GSPH faculty members recently were awarded funding for their research.

• Jessica Griffin Burke of the Department of Behavioral and Community Health Sciences received $203,000 from the National Institute on Drug Abuse for her study on patterns of substance use among HIV positive and negative men.

• Yue Chen of the Department of Infectious Diseases and Microbiology received a Grand Challenge Exploration Grant of $100,000 from the Bill and Melinda Gates Foundation to develop an oral vaccine against HIV using Clostridium perfringens bacteria as a delivery strategy.

The proposed vaccine strategy appears promising due to its safety, low production cost and ease of administration.

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The University Times Research Notes column reports on funding awarded to Pitt researchers as well as findings arising from University research.

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