THURSDAY, Sept. 4, 2014 (HealthDay News) -- Female animals or cells are rarely used in surgical research studies, even though sex differences can have a major impact on medical research, a new study finds.
The finding has prompted the editors of five major surgical journals to require study authors to report the sex of animals and cells used in their research. If they use only one sex, they will have to explain why.
"Women make up half the population, but in surgical literature, 80 percent of the studies only use males," study senior author Dr. Melina Kibbe, professor of surgical research at Northwestern University Feinberg School of Medicine, said in a Northwestern news release.
"We need to do better and provide basic research on both sexes to ultimately improve treatments for male and female patients," she added.
Kribbe and her colleagues analyzed more than 600 studies that included animal or cell research and were published in the journals Annals of Surgery, American Journal of Surgery, JAMA Surgery, Journal of Surgical Research, and Surgery from 2011 to 2012.
Twenty percent of the studies that used animals did not specify the sex of the animals. In studies that did state the sex of the animals, 80 percent used males, 17 percent used females and 3 percent used both.
Seventy-six percent of the studies that used cells did not specify the sex. In those that did state the sex, 71 percent used male cells, 21 percent female cells and 7 percent used cells from both sexes.
The study was published recently in the journal Surgery.
It's known that males and females differ in how they metabolize drugs, show symptoms of disease and respond to treatments.
"Requiring the sex of animals and cells is a very small thing to ask of authors. It should be a requirement of all medical journals," Kibbe said.
"The majority of research is based on the study of male animals and cells, and this practice does harm to both sexes," she explained. "By studying therapies and drugs in males and females, we will develop better drugs that will be more efficacious and lead to less adverse effects in both sexes."
The U.S. National Institutes of Health is developing a policy that will require all researchers that it funds to study both sexes in animal and cell studies.
The U.S. National Library of Medicine has more about women's health.