Heart-Related Results of Wayne State Study of Birth Control Pills Incorrect
Federal health officials on Wednesday said that a new analysis by senior statisticians suggests that the heart disease findings of a Wayne State University oral contraceptive study were "flawed" and other findings also are considered suspect, the AP/Yahoo! News reports (Marchione, AP/Yahoo! News, 12/16). The WSU study, led by Dr. Rahi Victory and presented in October at the annual meeting of the American Society for Reproductive Medicine in Philadelphia, found that women who use oral contraceptives have lower risks of uterine and ovarian cancers, heart disease, stroke and elevated cholesterol levels and no increased risk of breast cancer.
Victory and colleagues studied data from the $625 million, NIH-funded Women's Health Initiative, which includes information on 162,000 women throughout the United States, 67,000 of whom had taken oral contraceptives at some point in their lives. According to the WSU study, the risk of hypertension, heart attack, stroke, aneurysm and high cholesterol was reduced 8% to 10% among women who had taken oral contraceptives, and the risk of needing surgical procedures -- such as angiograms and bypasses -- was reduced 20% to 50%. In addition, the researchers said that women who had taken oral contraceptives also had a 7% lower risk of developing any type of cancer, an 18% lower risk of developing uterine cancer and a 19% lower risk of developing ovarian cancer than women who had never taken oral contraceptives.
Although the WSU study relied on WHI data, NIH officials last week distanced themselves from the WSU study, saying that it was unauthorized by WHI and contained flawed findings because the WHI study was not intended to evaluate the health effects of oral contraceptives (California Healthline, 10/21).
Statisticians at the WHI Clinical Coordinating Center, who have conducted new analyses using the WHI data, determined that the WSU study's finding that oral contraceptive use decreased a woman's risk of developing heart disease later in life is "flawed," Dr. Barbara Alving, director of WHI and acting director of the National Heart, Lung and Blood Institute -- which funds and oversees the WHI study -- said. Once the age of WHI study participants and other factors were taken into consideration, no relationship between contraceptive pill use and heart disease could be found, according to Alving, the AP/Yahoo! News reports.
Overall, the WHI study does not lend itself to determining the risks and benefits of oral contraceptive use because it relied on data self-reported by women -- and not confirmed with hospital or medical records -- about their history of health problems and prescription drug use, Alving said, adding, "There is room for a lot of bias to be introduced." In addition, the WSU study was not "properly reviewed" by the WHI researchers or government officials before it was published, according to Alving, the AP/Yahoo! News reports. Alving said the flaws of the study also call into question its other findings, including the conclusion that oral contraceptive use does not increase a woman's risk of developing breast cancer (AP/Yahoo! News, 12/16). Any analysis and results from the WSU study "are limited and considered exploratory, and they should not be used to reassure women about [oral contraceptive] use," Alving said (NIH release, 12/15).
WSU scientists currently are reviewing their findings and have not commented on the NIH and WHI statements about their study, according to John Oliver, vice president for research at WSU. "They want to look at the data," he said, adding, "They're in contact with the Women's Health Initiative about how to proceed."
WSU already has apologized in a statement for any "confusion" caused by the study findings, which it is now calling "preliminary," according to the AP/Yahoo! News. WSU officials said researchers are expected to release the complete results of their study as soon as they become available (AP/Yahoo! News, 12/16).