Until recently, studies of women's health received scant research attention in the context of the overall magnitude of research conducted on health. Even for health issues that affect both men and women, most research has been limited to male subjects, leaving a large gap in our knowledge base concerning women's health. Finally, the decade of the 1990s is ushering in a shift in this inequity. In 1990 the U.S. National Institutes of Health issued a compelling report citing the lack of sufficient research on women's health as a major gap in our knowledge, and a mandate has been issued to add...