Only the best science belongs in court: Limits on witness testimony needed

Most patients wouldn't want to receive treatments that haven't been generally accepted in the medical community, so why should scientific evidence introduced in the courtroom be treated any differently?

It shouldn't.

But one New York appellate court recently didn't seem to see the problems that judges can create when they admit evidence from an expert witness based on a novel theory that relies on a single case report. Yet it's no stretch to imagine the fallout. Companies pull good medications from the market altogether. More meritless lawsuits clog up the already-loaded-down legal system. Patients may shy away from lifesaving drugs.

The New York court, in Zito v. Zabarsky, incorrectly ruled that a woman who developed an autoimmune disease, polymyositis, can go forward with a lawsuit against the makers of Zocor (simvastatin), even though her experts did not present information that is generally accepted in the scientific community or in peer-reviewed literature.

Instead, her experts put forth a theory of how Zocor and polymyositis are linked. The only scientific literature they could produce was a single, one-page case report from a hospital in Italy published in The Lancet in 1997.

That one-page report -- as other courts have recognized -- is scientifically unreliable because it is simply an account of one patient and makes little attempt to screen out alternative causes for a patient's condition. And in this case in particular, the patient profiled in The Lancet had had major dissimilarities from the New York patient.

The New York court's decision to allow the woman's case to go forward based on this evidence flies in the face of years-old case law that established the importance of peer-reviewed scientific evidence and expert testimony that generally is accepted in the expert's field. In 1923, a court in the District of Columbia recognized what is known as the Frye standard, ruling that expert witnesses' testimony must have "general acceptance" in the field to be admissible. New York courts have followed this standard for years, and with good reason.

The National Academy of Sciences and the American Assn. for the Advancement of Science have warned that allowing experts to present novel theories in court "can unwittingly inject bad science into broader decisionsaffecting society."

The Food and Drug Administration has said that letting lawsuits go forward simply on unproven causation theories would wrongly allow "lay judges and juries to second-guess the assessment of benefits versus risks of a specific drug to the general public." The FDA further cautioned that allowing lawsuits such as the one in New York could "potentially discourage safe and effective use of approved [pharmaceutical] products."

On top of that, lawsuits admitted on scientifically unproven theories can lead to meritless litigation against companies that produce products that are safe and physicians who prescribe the FDA-approved medication.

In the words of 7th U.S. Circuit Court of Appeals Judge Richard A. Posner, in a 1996 opinion, "The courtroom is not the place for scientific guesswork, even of the inspired sort. Law lags science; it does not lead it."

Doctors agree with those assessments, leading the American Medical Association/State Medical Societies Litigation Center and the Medical Society of the State of New York to file a friend-of-the-court brief. They used the arguments above to urge the appellate court to change its initial ruling that allows the Zito lawsuit to go forward.

Unfortunately, the court in May denied a motion asking it to reconsider its stance.

Physicians are expected to use the best science available to make sure they are treating patients with the best possible care. Judges should screen medical expert testimony in order to ensure that jurors are getting the best scientific information upon which to base their decisions. Those courtroom decisions could have an impact on doctors and their patients for years to come.