Experts On The Experts: A Deep Dive Into The Make-or-Break Scientific Testimony Deciding Talc Powder Trials

Posted by on March 9, 2017

This article previously appeared on Courtroom View Network.

Dr. Graham Colditz and Application of the Bradford Hill Criteria

Expert testimony is often a critical component to prevailing in high stakes litigation.  Finding and vetting the ideal expert can be a challenge for the trial team but developing expert witnesses can be the difference between a positive outcome and costly defeat.  Likewise, preparing for the cross examination of opposing experts is equally important and can be one of the most vexing obstacles on the way to victory. Courtroom View Network (CVN) provides one of the most valuable tools available to assist with your expert-related activities, especially when the subject matter is medical or scientific in nature.

CVN is the first news media company to provide gavel-to-gavel video coverage of high-stakes civil trials like the one currently taking place in Missouri state court over the alleged cancer risks associated with Johnson & Johnson’s popular personal hygiene products containing talc powder, like Baby Powder and Shower to Shower. CVN also recorded two of the previous three Missouri talc trials in 2016, both of which ended in headline-grabbing plaintiffs verdicts that rested largely on the testimony from expert witnesses, and are among the hundreds of trials available in CVN’s unique online video archive. 

At Innovative Science Solutions, LLC (ISS) we use CVN to evaluate testimony of expert witnesses while they are on the stand in real courtroom situations. This approach allows us to get a sense as to which experts might be particularly effective testifiers. We have found that there is no substitute for viewing the expert “in action” to get a good sense as to how his or her testimony played, whether we would recommend this expert to a client, and/or how one might best go about substantively cross examining this expert if he or she were on the opposing side. 

As an example, we recently viewed testimony from a 2016 talc trial (Ristesund case) by Graham Colditz, an epidemiologist called by plaintiffs. Dr. Colditz is a prominent scientist in the medical community, currently Deputy Director, at the Institute for Public Health at Washington University in St. Louis. He has a longstanding interest in the preventable causes of chronic disease, particularly among women. His past research has focused on the health effects of smoking and the adverse effects of medications such as postmenopausal hormone therapy, and he has testified in the recent talc trials taking place in Missouri and New Jersey.

In a portion of his direct examination from 2016, plaintiff counsel asked Dr. Colditz how he knew that talc caused ovarian cancer. Colditz replied that the available evidence linking talc to ovarian cancer satisfies the Bradford Hill criteria and that this fact was central to his causation opinion. 

Here is an excerpt from the Q&A: (Click here to see full gavel-to-gavel video of the testimony)

Counsel: Okay, and is that– is that a recognized methodology to prove cause and effect in the epidemiology world?

Colditz: Oh, it’s the bread and butter of everything we have achieved [inaudible] trained to look at.

Counsel: And did you follow that methodology in arriving at your opinions today?

Colditz: Absolutely, that’s the approach I take to look at these issues.

Counsel: And this is well-recognized among your peers as the proper methodology to assess cause and effect, is that correct?

Colditz: Oh, fundamental in epidemiology, yes.

We have written on the importance of using criteria like this to establish causation in pharmaceutical product liability or toxic tort cases involving alleged injury to a drug or chemical exposure. Briefly, the Bradford Hill criteria are a set of guidelines that evaluate the amount and type of evidence making the link between the exposure and the injury. For example, the Bradford Hill criteria call for the evaluator to determine whether the quantitative associations between the exposure and the injury are large or small, whether they obtained consistency across multiple studies, and whether a dose response relationship has been established. Systems like the Bradford Hill criteria allow the expert to effectively combat anecdotal evidence. It puts epidemiology into an appropriate narrative structure, and appropriate utilization of this approach has been shown to be extremely effective for both plaintiffs and defendants in the litigation arena.

Dr. Colditz’s findings have been critical in two of the key jurisdictions where talc cases are centralized, Missouri and New Jersey. While allowed to testify in Missouri (including at the current trial), where the bulk of pending talc cases are filed, Dr. Colditz saw his potential testimony rejected by a New Jersey state court judge in October 2016. Judge Nelson Johnson in Atlantic City ruled that Colditz and another key plaintiff expert witness used scientific methodologies that are “slanted away from the objective science and toward advocacy.”

That decision resulted in the scuttling of the first planned talc trial in New Jersey, however the plaintiffs have appealed the judge’s ruling.

So, what was Colditz’s position on whether the Bradford Hill were met for talc and ovarian cancer?

According to Colditz, the data on genital talc use and ovarian cancer meets the Bradford Hill criteria in the same way that data on smoking and lung cancer meet the Bradford hill criteria. This is an interesting position because it sets the stage for the direct examination as well as the potential for cross examination on the merits of the science. Specifically, plaintiff counsel walked Dr. Colditz through each of the Bradford Hill criteria and asked him to testify as to whether the available scientific evidence appropriately met that criterion.

Notably, this approach also gives defense counsel a framework through which to cross examine Dr. Colditz. Specifically, defense counsel can take each criterion and cross examine Dr. Colditz as to, in their view, how the evidence fails to meet that criterion.

The defense’s cross-examination of Dr. Colditz, by both attorneys for Johnson & Johnson and their talc supplier, Imerys Talc America, centered largely on the argument that his testimony focused on a potential general causal relationship between talc and cancer and not a specific causal relationship to the actual plaintiff in the case. They detailed a range of potential causes for ovarian cancer (aside from talc powder) that could not be definitively ruled out, such as continual ovulation or family history, arguments raised by counsel for Johnson & Johnson during opening statements in the current case. The defense attorneys also confronted Colditz with decisions by numerous regulatory agencies and watchdog groups not to label talc powder a carcinogen. 

The bottom line is that watching Dr. Colditz testify on CVN as to the scientific evidence linking genital talc use to ovarian cancer is an excellent way to determine plaintiff best case as well as what might constitute the most effective defense response. 

David H. Schwartz, Ph.D. is a founding partner of Innovative Science Solutions, LLC, a consulting firm that specializes in assisting counsel with litigation involving complex scientific issues, including toxic torts, pharmaceutical and medical device cases, consumer fraud cases, and patent disputes.