Court ruling on expert testimony could open door to junk science

Andis Robeznieks , Senior News Writer

The New Jersey Supreme Court is expected to issue a ruling soon that may affect more than 2,000 cases before the state’s courts. The court’s decision could have an even more far-reaching impact and might eventually undermine medical research, patient-physician decision making and informed consent.

The issue is whether scientific testimony expressing refuted theories that have not been subjected to peer review and do not follow the traditional hierarchy of scientific evidence should be admissible in litigation involving plaintiffs who claim their inflammatory bowel disease (IBD) was caused by the drug isotretinoin, marketed as Accutane by Hoffmann-La Roche, formerly headquartered in Nutley, N.J.

The first lawsuit on this matter was filed in July 2003. A hearing on whether the plaintiffs’ witnesses would be allowed to testify was held in February 2015, after which trial Judge Nelson C. Johnson barred their testimony. In May 2015, Johnson dismissed 2,076 related cases based on his ruling about the evidence.

This past July, a three-judge panel of the state appellate court reversed both the ruling barring the testimony and the dismissal of the cases. Hoffman-La Roche has requested the state Supreme Court to review this ruling.

The Litigation Center of the American Medical Association and State Medical Societies filed an amicus brief in support of Hoffmann-La Roche. The Medical Society of New Jersey, the American Academy of Dermatology and other medical organizations joined in the friend-of-the-court filing.

The brief notes the negative impact the appellate ruling could have if it’s allowed to stand.

“Medical testimony based on junk science reaches far beyond the case at hand and infects physicians’ offices nationwide, skewing patient care away from proven treatment,” the brief states. “Patients, physicians and our system of justice all suffer when courts permit outlier experts to confuse juries with disproven theories based on scientifically unsound methodologies that contradict peer-reviewed medical studies.”

The brief states that isotretinoin was approved in 1982 for treating the most severe form of acne, and it acknowledges that the drug has the potential to cause fetal malformations—that is why its use is tightly controlled. Some physicians reported in the 1980s that isotretinoin users occasionally were diagnosed with IBD, including Crohn’s disease, which plaintiffs said they developed as a result of taking the drug.

“Correlation, of course, is not necessarily causation,” the brief argues. “The theory that isotretinoin increases the risk of inflammatory bowel disease has been debunked by numerous peer-reviewed studies.”

The testimony offered by the plaintiffs’ witnesses not only lacked corroboration, but directly conflicts with existing high-quality evidence disproving a link between isotretinoin and the risk of developing IBD, the brief states. Judge Johnson agreed.

“It is one thing to stand alone in the world of science, advancing a hypothesis that others do not accept,” Johnson wrote. “It is quite another thing to advance a hypothesis that can only be supported by disregarding valid scientific research.”

The appellate panel, however, ruled that “the trial court went beyond its gatekeeping function,” and that Johnson ruled too narrowly in determining “the weight and credibility” of the plaintiffs’ experts.

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In their decision, written by Judge Susan Reisner, the appellate judges said it wasn’t their role to predict whether a jury would find either the plaintiffs’ or the defendants’ experts credible or persuasive.

“In some cases, a court may conclude that there is simply too great an analytical gap between the data and the expert's opinion,” Judge Reisner wrote. “However, in this case, we conclude that the data was sufficient to permit the experts to testify, and any weaknesses in their opinions can be explored through cross-examination.”

The amicus brief argues the appellate court’s ruling “imbues the medical decision-making process with court-approved, unsound scientific testimony.”

Once an expert opinion gets the court’s seal of approval, the brief explains, “It can be difficult for physicians to counteract it outside the courtroom.”

The brief catalogues a cascade of negative results that pose dangers to patients who need treatment.

“By permitting expert testimony that flies in the face of the overwhelming consensus of valid scientific research, the court tells physicians that this unsubstantiated information is relevant and therefore may (or must) be disclosed to patients, either purely based on relevance or out of fear of litigation, regardless of whether it is based on principles of sound science,” the brief states. “As a result, patients may decline these treatments out of fear based on discredited theories, or practitioners may veer away from recommending certain reliable treatments altogether.”

The brief notes that “not all evidence is created equal,” and cites two JAMA Dermatology studies in illustrating how evidence is hierarchal, with randomized clinical trials and large epidemiological studies at the top and unsystematic clinical observations and case reports at the bottom.

For example, the 2013 JAMA Dermatology study cited in the brief involved U.S. and Canadian researchers examining more than eight years of records. They found no evidence to suggest an increase of IBD risk with use of isotretinoin.

In the 2014 study published in JAMA Dermatology, researchers examined five years of records in the Mayo Clinic database and came up with results that were both predictable and surprising.

“Our study did not show an increased risk of IBD with prior isotretinoin use,” the Mayo researchers concluded. “If anything, the risk seemed to be decreased.”

The amicus brief notes that the appellate court acknowledged the existence of the evidence hierarchy, but “neutered its significance.” In so doing, the court “lends legitimacy to unfounded theories and undermines medical research.”

Ultimately, the court’s decision could have the undesired consequence of undermining patients’ informed consent to medical treatment, which is “fundamental in both ethics and law,” the brief states, citing the AMA Code of Medical Ethics.