Federal officials Wednesday backed away from the findings of two major studies on birth control pills, saying the research was flawed and that a new analysis shows there is no evidence that oral contraceptives cut the risk of heart disease. John Oliver, vice president for research at Wayne State, said the scientists were reviewing their work and would have no comment now. "They want to look at the data. They're in contact with the Women's Health Initiative about how to proceed," he said. The university also issued a statement apologizing for any confusion caused by the studies, which it points out are preliminary, and pledged to publish full results whey they are available.