Though they comprise a significant proportion of the heart disease population, women and the elderly remain underrepresented in cardiovascular clinical trials, a new study finds. Writing in the current issue of the Journal of the American Medical Association, the Duke University scientists who conducted the research note that because the safety and efficacy of drugs against heart disease can vary according to sex and age, "these enrollment biases undermine efforts to provide evidence-based care to all cardiac patients."

The Duke team examined 593 randomized clinical trials investigating heart attack and unstable angina that had been published between January 1966 and March 2000. Although they did find an increase in the representation of women and the elderly in these trials over time, that trend was modest. Inclusion of the elderly in such trials rose from 2 percent in 1966 to 9 percent after 1990. Yet this group makes up nearly 40 percent of all heart attack patients in the U.S. Similarly, although the percentage of female subjects in these trials rose from 20 percent in 1966 to 29 percent after 1995, women account for 43 percent of heart attack patients.

"The universal extension of trial results from a younger, mostly male population to women and elderly patients may be inappropriate," team member Eric Peterson notes. "This paucity of information regarding the safety and efficacy of therapies in women and elderly patients may lead some physicians to withhold treatment in these subgroups.