Early clinical trials "tend to enroll relatively healthy white males but few children, women, minorities and older patients" -- a disparity that can result in research that "ignores biological differences that cause people of varying ages, genders and ethnicities to react differently to therapies," the Baltimore Sun reports.
According to the Sun, "therapies that perform well in clinical trials often prove less effective -- and sometimes more dangerous -- when put to widespread use," according to the Sun. In addition, some trials might not show any benefits for white males, but the therapies might be helpful to minorities.
Rita Redberg, a cardiologist at the University of California-San Francisco, said, "We are extrapolating from a clinical-trial population that looks nothing like the general population." According to a 2001 FDA study of 185 drug trials that took place between 1995 and 2000, half of the participants were women, while the proportion of blacks in enrolled trials declined from 9% in 1995 to 6% in 1999. The study found that few other minorities participated in clinical trials and that the number of Hispanic participants was particularly low.
According to experts, women of childbearing age are reluctant to participate in clinical trials because of possible harm to developing fetuses, while blacks "tend to be generally more distrustful of the medical establishment than other groups," and older patients are more likely to have multiple conditions, complicating the results of the study, the Sun reports.
The sampling problem "puts the FDA, Medicare and private insurers in the difficult position of using narrowly focused data to decide which drugs will be used in a broad population of patients," according to the Sun. Congress in 1993 passed a law that encourages federally funded trials to include women and minorities, and FDA has begun encouraging companies to report gender- and race-specific trial data.
Terry Eigo, director of the FDA's Office of Special Health Issues, said, "The message is that we encourage diversity in research." She added that the agency does not mandate sampling diversity because if it "required substantial numbers of people in every subgroup, the size of the trials would be massive," and it is "likely that the benefits would not be worth the cost".
Source: Kaiser Family Foundation