Gender representation in trials

The perception is that women have been understudied relative to men. It has been sufficient to cause Congress to enact legislation to require that a c linical trial must be "designed and carried out in a manner sufficient to p rovide for a valid analysis of whether the variables being studied in the t rial affect women... differently than other subjects in the trial." We look ed for evidence as to whether the perception has a basis in fact by looking at measures of gender-based research effort. Clinical trials, published be tween 1966 and 1998 in U.S. journals and indexed in MEDLINE, were classifie d by gender. Reports of trials (n = 724) appearing in five widely circulate d medical journals (Annals of Infernal Medicine, British Medical Journal Jo urnal of the American Medical Association, Lancet, and New England Journal of Medicine) in 1985, 1990, and 1995 were retrieved and read to obtain coun ts of the numbers of males and females represented in trials published in t hose journals. For reports of trials published in U.S. journals (n = 100,45 5), the percent involving males and females, males only, females only, and those where gender was not specified were 55.2%, 12.2%, 11.2%, and 21.4%, r espectively. Counts of males and females represented in the reports of tria ls appearing in the five aforementioned journals were 355,624 and 550,743, respectively. We did not find evidence of systematic effort bias against fe males. (C) Elsevier Science Inc. 2000.