In a court of law, plaintiff and defense lawyers often present scientific experts to support their contentions. Whose scientists are correct? How do a judge and jury determine which scientific experts are credible?
Using the silicone breast implant litigation as an example, James T. Rosenbaum, M.D., professor of medicine at Oregon Health Sciences University, illustrates how scientific testimony can conflict. His policy recommendations appear in the June 6, 1997 issue of the journal Science. Rosenbaum offers suggestions to improve the reliability and independence of scientific expert testimony in the courtroom.
"Scientific bodies should not wait for the court to seek advice; as scientists we should ensure that every court has at its disposal a listing of neutral experts with specified areas of expertise and acknowledgment of potential conflicts," says Rosenbaum.
Using the breast implant litigation as an example, Rosenbaum suggests two solutions to potential conflicts: either allow the court to appoint experts to testify or empanel a group of experts to advise the court. He notes that the National Institutes of Health maintains a roster of potential scientific experts who are checked for conflicts of interests. Other resources for scientific guidance are the American Association for the Advancement of Science and the National Academy of Sciences.
"In the case of silicone implants, juries need unbiased guidance to fathom the immunology, epidemiology, biochemistry and pathogenesis of autoimmune disease," explains Rosenbaum. In August 1996, U.S. District Court Judge Robert E. Jones heard arguments on the scientific admissibility of evidence relative to alleged silicone disease. The Ninth Circuit Daubert opinion has noted, "Though we are largely untrained in science and certainly no match for any of the witnesses whose testimony we are reviewing, it is our responsibility to determine whose experts' proposed testimony amounts to 'scientific knowledge,' constitutes 'good science,' and was derived from the scientific method."
With the aid of a scientific adviser, Richard Jones, M.D., Ph.D., former chairman of biochemistry at OHSU, Judge Robert E. Jones enlisted four neutral panelists to advise on the admissibility of opinions offered by the plaintiffs' experts for lawsuits involving silicone breast implants pending in his jurisdiction.
Using the report from the panel, Judge Jones ruled that the plaintiffs' "scientific" experts could not offer opinions on causation issues. In reaching this conclusion, Judge Robert E. Jones noted that the opinions of the scientists hired by the plaintiffs were not based on tested hypotheses; their analyses of experimental studies involved an extrapolation that represented a "leap of faith"; no study had found an increase in relative risk greater than 2 for any disease; the proposed experts had relied on differential diagnosis, a process that is not reliable in establishing causation; and their opinion differed from the prevailing consensus.
"Although this opinion is having a far-reaching effect," explains Rosenbaum, "it is not binding on state courts where the vast majority of implant cases are being tried. Nor does the ruling bind other federal district courts. One other federal judge who has been assigned breast implant litigation is also seeking advice from a similar panel. In two other federal cases, courts have limited the testimony on causation by the plaintiffs' experts.
"The proceedings before Judge Robert E. Jones demonstrate the appropriate use of a scientific advisory panel. Although this approach entails some expense, the cost is trivial compared to the $50 billion at stake in the silicone breast implant litigation. Although scientific 'truth' is not immutable, the courts have recognized that scientific arguments for causation must meet definable standards and that scientists themselves, either as experts appointed by the court or as advisers to the court, are best qualified to judge science."
Rosenbaum further explains that breast implant litigation is just one example of the need for courts to seek scientific advice. "Regardless of how one feels about breast implants, the 'plea' in my article is for scientists to volunteer in an organized fashion to advise judges and juries."