By Will Dunham
WASHINGTON, Jan 14 (Reuters) - Distrust of doctors and concern over being abused as human guinea pigs may explain why U.S. blacks have been less willing than whites to volunteer to take part in medical studies, researchers said on Monday.
Experts have known for decades that blacks are more reluctant than whites to take part in clinical trials, which are vital in testing the effectiveness of new treatment, prevention and diagnosis methods for various diseases.
But if a study of a new drug, for example, involves mostly white volunteers, there can be doubts on whether its results are applicable to everyone.
Researchers at Johns Hopkins University in Baltimore went through the process of recruiting volunteers to take part in a mock clinical trial testing a pill to treat heart disease.
Their study involved 717 patients -- about a third black and the rest white -- at 13 medical clinics in Maryland. They found that blacks were about 40 percent less willing to participate in the mock clinical trial.
The researchers asked a series of questions to learn why people did or did not want to volunteer.
They found that 58 percent of blacks, compared to just 25 percent of whites, said they believed doctors use drugs to experiment on people without a patient's consent.
In addition, 25 percent of the blacks, compared to 15 percent of whites, expressed the belief their doctor would be willing to ask them to take part in a study even if the study might harm them. And 28 percent of blacks, compared to 22 percent of whites, said their doctors would be willing to expose them to unnecessary risks.
"African American participants expressed markedly greater concerns about experiencing harm from participation in clinical trials and distrust toward medical researchers than white participants," the researchers wrote in the journal Medicine.
"These factors, in turn, appear to explain much of the resistance among African American persons to participate in clinical trials compared to white persons," they added.
Dr. Neil Powe, one of the Johns Hopkins researchers, said the reluctance of the blacks to volunteer may be a legacy of past abuses like the infamous Tuskegee syphilis experiment.
"That may have led to distrust of medical research, particularly by African Americans," Powe said in a telephone interview.
In that 40-year, government-sponsored experiment, hundreds of black men in Alabama with syphilis were brought into a study in which researchers withheld proper medical treatment in order to document what happens to men with untreated syphilis.
Some researchers have tried to better understand racial disparities in medicine, including the fact that blacks are more likely than whites to develop certain types of diseases as well as getting different treatment than whites.
Last week, other researchers reported that U.S. blacks continue to get inferior cancer treatment compared to whites. They looked at lung, breast, colon, rectal and prostate cancer, and found that black patients consistently were less likely than whites to receive the recommended types of treatment.
(Editing by Maggie Fox and Jackie Frank)
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