A new scientific study challenges the validity of medical research done more than a decade ago that was crucial in condemning the Dalkon Shield and other intrauterine contraceptive devices as dangerous.
While the new study does not go so far as to exonerate the Dalkon Shield specifically, it concludes that intrauterine devices in general do not increase the risk of pelvic infection. That finding directly contradicts the conclusion of the original federally financed study.
The latest finding, published in the current issue of The Journal of Clinical Epidemiology, is not meant to suggest a course of action by women. But it is certain to renew debate about the value of IUD's, which are now used by an estimated 1.5 million women in this country, or 3 percent of contraceptive users, less than half the number in 1982. The devices are placed in the uterus to prevent pregnancy, but scientists do not know precisely how they achieve their effect.
'Good Solid Work'
The American College of Obstetricians and Gynecologists said it was taking the new report seriously "because it appears to be good solid work and it appeared in a very good journal," said Dr. Harold Kaminetzky, an official of the group in Washington.
A committee will begin evaluating the report this week. "If the argument made is true, it will have profound significance on the use of IUD's in general," said Dr. Kaminetzky, whose group publishes Obstetrics and Gynecology, the journal in which reports of the original study appeared.
The latest report, using the raw data from the original study of more than a decade ago, was supervised by a researcher who had been a consultant to the Dalkon Shield's manufacturer, the A.H. Robins Company of Richmond.
The researcher, Dr. Richard A. Kronmal of the University of Washington, said in an interview that he waited all these years to respond to the original study because he was concerned that he would be seen as biased in favor of Robins, as though "they had hired me to write this paper," and thus his statements "would not get a fair reading from scientists." He also said he was reluctant to publish while lawsuits over the shield were still going on.
Original Study Defended
In response to the newest study, the authors of the original research, known as the Women's Health Study, defended their work as valid.
The Women's Health Study, published in 1981, played a central role in the litigation that led A.H. Robins to seek protection under Federal bankruptcy laws. The Women's Health Study was also cited in litigation against manufacturers of other intrauterine devices, leading them to withdraw most such devices from the American market and to reduce research in contraception.
A $2.5 billion trust fund, meant to compensate more than 100,000 women who have sought damages for health problems they attributed to use of the Dalkon Shield, was created when Robins was acquired by its present parent, the American Home Products Corporation of New York. The new study could have some effect on the nearly 100,000 claims still being made on the trust fund, lawyers said.
Claimants who can prove causal injury are offered a non-negotiable settlement, but can reject it and seek a jury trial or arbitration. In such a proceeding, any new medical evidence, like the latest study, could be cited, said Douglas E. Bragg, a Denver lawyer who represents women with claims against the Dalkon Shield.
Many experts have faulted the Dalkon Shield for its design, which differed from other IUD's in having a tailstring that could draw bacteria from the vagina into the uterus.
Methodology Is Faulted
Based on a re-analysis of the original data, the authors of the new report concluded that the Women's Health Study "showed an almost complete disregard for epidemiologic principles in its design, conduct, analysis and interpretation of results."
The new report was written by Dr. Kronmal and Dr. Coralyn W. Whitney, both members of the University of Washington's Department of Biostatistics, which other medical experts rate one of the best such departments in the country. The third author was Dr. Stephen D. Mumford of the Center for Research on Population and Security in Research Triangle Park in North Carolina.
Dr. Kronmal and Dr. Mumford emphasized in the report that they had been expert witnesses for A.H. Robins in court proceedings. Dr. Kronmal said he hired Dr. Whitney, who was a graduate student at the time the analysis was made in 1983.
Dr. Thomas J. Petrick, an official of Family Health International, a nonprofit research organization in family planning in Durham, N.C., said he would "suggest that a third, disinterested party look at the same data."
When the Dalkon Shield was first marketed in 1971, there was no requirement that such devices be approved by the Food and Drug Administration, and critics have faulted the original studies evaluating the effectiveness of the Dalkon Shield. One criticism was that some patients in the trial used vaginal spermicide contraception along with the Dalkon Shield.
Taken Off the Market
In 1974, the F.D.A. asked A.H. Robins to remove the Dalkon Shield from the market because of reports of life-threatening septic abortions and other pelvic infections in some women. Later that year, the F.D.A. said the company could resume sales under a system in which A.H. Robins would have kept a registry of the names of patients, but it declined to do so.
Further reports of pelvic infections led A.H. Robins in 1980 to advise doctors to remove the Dalkon Shield from those still using it.
The National Institutes of Health sponsored the Women's Health Study beginning in 1976 to assess the relationship between IUD's and pelvic infections among patients in 16 hospitals in 9 cities. The study, which ended in 1978, concluded that IUD's in general increased the risk of pelvic infections by 60 percent. But part of the study compared two types of IUD's other than the Dalkon Shield and found no increased risk of infection for either.
In 1983, researchers at the Centers for Disease Control in Atlanta used data from the Women's Health Study to compare five IUD's, including the Dalkon Shield, with each other and with no method of contraception. The Dalkon Shield was found to have a substantially higher risk of pelvic infection compared with other IUD's and with no method of contraception.
Studies' Findings Conflict
Findings from several newer studies have conflicted with the earlier ones, and experts have attributed most such differences to variations in methods.
The newest study is believed to be the only one to use the raw data from the Women's Health Study since it was published. In his analysis, Dr. Kronmal used a set of 12 points that other researchers developed to evaluate the statistical and other technical methods used in studies like the Women's Health Study.
The Women's Health Study "violated, in one way or another, 10 of the 12 standards," Dr. Kronmal's team said. But the team conceded that the Women's Health Study was "probably the best conducted of" the studies implicating IUD's as a cause of pelvic infection.
Many violations involved the way the researchers selected the women used for purposes of scientific comparisons, Dr. Kronmal's team said.
Dr. Kronmal's team said the Women's Health Study results were biased because the study seriously deviated from a general epidemiologic principle. The principle calls on scientists to set the method of choosing two groups -- one of people with the particular condition being studied and the other closely matched for purposes of comparison -- before data are obtained and analyzed. The intention is to avoid influencing the results by manipulating the composition of each group.
Were Memories Biased?
The Women's Health Study authors eliminated 52 percent of cases and 25 percent of controls "for reasons that have no basis in science," Dr. Kronmal reported.
Because of the adverse publicity about IUD's at the time of the Women's Health Study, Dr. Kronmal's report said the results could have been affected by possible biases in patients' memories about their medical care.
The new report also said that doctors may have been more inclined to diagnose pelvic infections in Dalkon Shield users, and that if a small number of doctors did so the results could have changed significantly.
Dr. Kronmal found that the Dalkon Shield had a higher risk than other IUD's for pelvic infection. However, Dr. Kronmal said there was no way to determine whether the higher risk was due to a cause-effect relationship or to selection and other biases.
The Journal of Clinical Epidemiology also published a reply to the criticism from authors of the Women's Health Study, who were headed by Dr. Ronald T. Burkman, now of Henry Ford Hospital in Detroit.
Dr. Burkman's team defended its study and said Dr. Kronmal's report was "replete with factual error, misrepresentation and overstatement." The team said that it had acknowledged many of the concerns raised by Dr. Kronmal in its papers and did not violate epidemiologic principles. Although the study was imperfect, the authors said, "it contributed substantially to our understanding of the morbidity associated with use of an IUD."
In an interview, Dr. Burkman urged scientists to read the articles and reach their own conclusion. As if to emphasize that he was not against all IUD's, Dr. Burkman said he had inserted an IUD in a patient just before the interview.
Only two IUD brands are now marketed in the United States. One is Paragard, which is manufacturered by Gynopharma Inc. of Somerville, N.J., and the other is Progestasert, which is manufactured by the Alza Corporation of Palo Alto, Calif.
Elsewhere, IUD's continue to be the most widely used reversible form of contraception. In China, for example, IUD's are used by about 40 percent of contraceptive users, including 29 percent of married women of reproductive age.
Population Reports, a journal published by Johns Hopkins University, has said that IUDs are more effective in preventing pregnancy than the oral contraceptive pill, condoms, spermicides and barrier methods.
Explaining the Delay
In explaining the delay in publishing, Dr. Kronmal said that his analysis was never used in court because "A.H. Robins, faced with increasing hostility from the scientific community and organized family planning providers, had already decided that continued defense of the Dalkon Shield was hopeless."
Joyce Dixon, a spokeswoman for A.H. Robins, and Carol Emerling, a spokeswoman for the parent company, said that on advice of lawyers they could not discuss Dr. Kronmal's statement and paper, and that the surviving company no longer had the records.
Grace Den Hartog, a lawyer for McGuire, Woods, Battle & Boothe in Richmond, which represented A.H. Robins, said her firm could not comment because it no longer had the files.
Even with blessings from professional organizations, several changes will be needed if IUD use is to increase in the United States. Women will have to overcome memories of the adverse publicity about IUD's. Many doctors will be reluctant to risk malpractice suits over infections whose source may not be clear. And manufacturers will want assurance they can obtain product liability insurance at a reasonable cost.
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