Court of Appeals Vacates Jury Verdict for Plaintiff in Welding Case

The Sixth Circuit last week vacated one of the rare plaintiff verdicts in the welding rod litigation.  Tamraz  v. Lincoln Electric Co., et al., 2010 WL  3489002 (6th Cir. 9/8/10).  The key issue in the appeal was the trial court's decision to allow a causation expert, Dr. Walter Carlini, to testify on behalf of the plaintiff Jeff Tamraz over defendants' Daubert challenge.

From roughly 1979 to 2004, Jeff Tamraz worked as an independent-contracting welder in California, on bridges and buildings.  Plaintiffs contended that Mr. Tamraz suffers from manganese-induced Parkinsonism as a result of exposure to manganese-containing welding fumes on these jobs.

The case went to trial in 2007, and the jury in the Northern District of Ohio (plaintiffs are from Oregon) returned a plaintiff verdict, awarding $17.5 million to Jeff Tamraz in compensatory damages and $3 million to his wife, Terry Tamraz, for loss of consortium.

Defendants, including Lincoln Electric, Hobart Brothers Co. and ESAB Group Inc., appealed on various grounds, including the trial court's decision to permit the testimony of Dr. Carlini on causation issues despite the Daubert challenge.

The opinion offers a number of useful observations for toxic tort litigation, especially on the almost-always central issue of causation.

It begins with a nice overview of the science on the spectrum of movement disorders often termed "parkinsonism" that have different causes and different but overlapping symptoms.  No one disputed that plaintiff here suffered from parkinsonism; the questions were what kind and from what cause. Apparently, every doctor to examine Tamraz reached a different conclusion about one or both of those issues.  Plaintiff's expert concluded that Tamraz suffers from “manganese-induced parkinsonism,” but not in the sense of a manifestation of the disease "manganism," as that phrase is sometimes used in these welding cases. Rather, he believed that manganese exposure caused something closely akin to traditional Parkinson's Disease in Tamraz.  Dr. Carlini hypothesized that Tamraz might have a genetic predisposition to Parkinson's Disease, and that manganese in lower levels than necessary to cause true manganism might nevertheless “trigger” the symptoms of Parkinson's Disease, like “the straw that broke the camel's back.” He did not believe that Tamraz has Parkinson's Disease in the strict medical sense, but manganese caused a disease that he believed to be otherwise similar to Parkinson's Disease. 

Defendants disputed this conclusion that manganese exposure caused the illness; that is, they challenged Dr. Carlini's etiology (what caused the disorder diagnosed?), not the methodology to arrive at his general spectrum diagnosis (what disorder caused the set of symptoms observed?).  And the Sixth Circuit agreed there were serious issues here. The problem here was that, when Dr. Carlini testified that manganese exposure caused Tamraz's condition, he went beyond the boundaries of allowable testimony under Rule 702.

The opinion was at most a working hypothesis, not admissible scientific “knowledge.” Fed.R.Evid. 702. His theory was a "plausible hypothesis. It may even be right. But it is no more than a hypothesis."  For example, the expert admitted that the literature hypothesizing a link between environmental toxins and latent genetic Parkinson's Disease was “all theoretical.”  He also conceded there were no studies finding a link between manganese and true Parkinson's Disease.  He further he conceded that he was speculating that Tamraz had an underlying predisposition to Parkinson's Disease, even though Tamraz had no family history of Parkinson's Disease. 

And finally, even if manganese could cause Parkinson's Disease in someone like Tamraz, that did not show that manganese did cause Tamraz's Parkinson's Disease. Parkinson's Disease occurs commonly in the general population and usually without any known cause. Any given case of Parkinson's Disease thus might have occurred regardless of the manganese exposure, making it hard to attribute one case to manganese exposure over all of the other possible causes.

Plaintiffs stressed on appeal that Dr. Carlini opined “with a reasonable degree of medical certainty,” but the court of appeals correctly noted that the phrase --the conclusion by itself-- does not make a causation opinion admissible. The “ipse dixit of the expert” alone is not sufficient to permit the admission of an opinion. General Elec. Co. v. Joiner, 522 U.S. 136, 146 (1997). Minus that one phrase, nothing in this testimony took the opinion beyond speculation, theory, hypothesis. 

Plaintiffs, understandably, also tried to bolster the opinion by emphasizing areas of agreement among experts on the general diagnosis of some parkinsonism disorder.  But in conflating “manganese-induced parkinsonism” with manganism, plaintiff conflated diagnosis with etiology, erasing the distinction between Tamraz's disease and what caused it. Diagnosis and etiology, however, both were in play in this case. Because Dr. Carlini diagnosed Tamraz with something akin to Parkinson's Disease, not manganism, and because Parkinson's Disease unlike manganism has no standard etiology and lots of idiopathic cases, Dr. Carlini's etiology opinion had to rise or fall on its own.

Plaintiffs also trotted out the standard "differential diagnosis" argument, the tent that supposedly (and too often does) covers all kinds of unreliable causation opinions from medical experts.  The court here made some very useful observations about this issue. 

1) Most treating physicians have more training in and experience with diagnosis than etiology. See D. Faigman, Judges as “Amateur Scientists”, 86 B . U. L.Rev. 1207, 1221-22 (2006); E. Imwinkelried, The Admissibility and Legal Sufficiency of Testimony About Differential Diagnosis (Etiology), 56 Baylor L.Rev. 391, 405 (2004); M. Henefin, Reference Guide on Medical Testimony, in Reference Manual on Scientific Evidence 439, 471-72 (2d ed.2000). 

2) When physicians think about etiology in a clinical setting, moreover, they may think about it in a different way from the way judges and juries think about it in a courtroom. 

3) Getting the diagnosis right matters greatly to a treating physician, as a bungled diagnosis can lead to unnecessary procedures at best and death at worst. See Bowers v. Norfolk S. Corp., 537 F.Supp.2d 1343, 1361 (M.D.Ga.2007). But with etiology, the same physician may often follow a precautionary principle: If a particular factor might cause a disease, and the factor is readily avoidable, why not advise the patient to avoid it? Such advice  --telling a worker, say, to use a respirator-- can do little harm, think the doctors, and might do some good. See J. Hollingsworth & E. Lasker, The Case Against Differential Diagnosis: Daubert, Medical Causation Testimony, and the Scientific Method, 37 J. Health L. 85, 98 (2004). A lower threshold for making a causation decision serves well in the clinic but not in the courtroom, said the court. 

Of course, some courts permit the physician to testify as to etiology using this methodology, e.g., Hardyman v. Norfolk & W. Ry. Co., 243 F.3d 255, 260-67 (6th Cir.2001), but even these courts must apply the Daubert principles carefully in considering it. The ability to diagnose medical conditions is not remotely the same as the ability to deduce, in a scientifically reliable manner, the causes of those medical conditions. Gass v. Marriott Hotel Servs., Inc., 501 F.Supp.2d 1011, 1019 (W.D.Mich.2007), rev'd on other grounds, 558 F.3d 419 (6th Cir.2009). Doctors thus may testify to both, at least in the Sixth Circuit, but the reliability of one does not guarantee the reliability of the other. 

Thus, whether plaintiffs described Dr. Carlini's causation methodology as “differential etiology” or “differential diagnosis,” that label does not make it reliable. Using the differential diagnosis method is not some "incantation that opens the Daubert gate.”  The issues remain, did the expert make an accurate diagnosis of the nature of the disease? Did the expert reliably rule in the possible causes of it? Did the expert reliably rule out the rejected causes? If the court answers “no” to any of these questions, the court must exclude the ultimate conclusion reached. See Best v. Lowe's Home Ctrs., Inc., 563 F.3d 171, 179 (6th Cir .2009).

Here, Dr. Carlini's opinion failed the last two prongs because his efforts to “rule in” manganese exposure as a possible cause, or to “rule out” other possible causes, turned on speculation and theory and hypothesis, not a valid methodology. 

While expressing sympathy for the plaintiffs, the court observed that ignoring Rule 702 — allowing the law to "get ahead of science" — would be just as unfair. Such an approach eventually would destroy jobs and stifle innovation unnecessarily, because it would impose liability on business based on speculation, not science.

Case remanded for new trial, with different evidence obviously. 

(The dissent would have found the challenge going to the weight, not admissibility of the testimony, and the trial court's decision not an abuse of discretion.)

General Causation Opinion Excluded by Eleventh Circuit in Autism Case

The Eleventh Circuit recently  affirmed a judgment for defendant Evenflo Co. in a suit by a plaintiff who had alleged that the car seat manufacturer was responsible for her son's autism. Hendrix v. Evenflo Co., 2010 WL 2490760 (11th Cir., 6/22/10).

Plaintiff alleged that her son sustained traumatic brain injuries when a child restraint system manufactured by Evenflo allegedly malfunctioned during a minor traffic accident. Hendrix further alleged that those brain injuries caused the son to develop autism spectrum disorder (“ASD”). The district court excluded testimony from two of Hendrix's expert witnesses that the accident caused the ASD, concluding that the methods used by Hendrix's experts were not sufficiently reliable under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993). See Hendrix v. Evenflo Co., Inc., 255 F.R.D. 568 (N.D.Fla. 2009). The lower court then granted partial summary judgment to Evenflo on Hendrix's ASD claim, determining that without the excluded testimony there was no reliable evidence to support Hendrix's theory that the accident caused the ASD. Hendrix voluntarily dismissed, with prejudice, her remaining damages claims and filed a notice of appeal.

Hendrix's experts relied primarily on the controversial differential etiology method to link the child's traumatic brain injury to his ASD diagnosis. Differential etiology, said the court, is a medical process of elimination whereby the possible causes of a condition are considered and ruled out one-by-one, leaving only one cause remaining. It is a questionable extension of the method by which doctors diagnose a disease into the area of what caused the disease.

The Eleventh Circuit has previously held that, when applied under certain circumstances that it thinks will ensure reliability, the differential etiology method can provide a valid basis for medical causation opinions. The reliability of the method must be judged by considering the reasonableness of applying the differential etiology approach to the facts of this case and the validity of the experts' particular method of analyzing the data and drawing conclusions therefrom. According to the court, a reliable differential etiology analysis is performed in two steps. First, the expert must compile a comprehensive list of hypotheses that might explain the set of salient clinical findings under consideration; the issue at this point in the process is which of the competing causes are generally capable of causing the patient's symptoms. See Clausen v. M/V New Carissa, 339 F.3d 1049, 1057-58 (9th Cir.2003). Second, the expert must eliminate all causes but one.

With regard to the first step, the district court must ensure that, for each possible cause the expert “rules in” at the first stage of the analysis, the expert's opinion on general causation is derived from scientifically valid methodology.  Hollander v. Sandoz Pharm. Corp., 289 F.3d 1193, 1211 (10th Cir.2002); Siharath v. Sandoz Pharms. Corp., 131 F.Supp.2d 1347, 1362-63 (N.D.Ga.2001). This is because a fundamental assumption underlying differential etiology is that the final, suspected cause must actually be capable of causing the injury. Thus, here, the experts' purported use of the differential etiology method will not overcome a fundamental failure to lay the scientific groundwork for the theory that traumatic brain injury can, in general, cause autism.

The Eleventh Circuit has distinguished cases in which the medical community generally recognizes that a certain chemical or product can cause the injury the plaintiff alleges from those in which the medical community has not reached such a consensus. In the second category of cases, the district court must apply the Daubert analysis not only to the expert's methodology for figuring out whether the agent caused the plaintiff's specific injury, but also to the question of whether the drug or chemical or product can, in general, cause the harm plaintiff alleges. Thus, the district court must assess the reliability of the expert's opinion on general, as well as specific, causation.  In this regard, the court (like most) rejects the “post hoc ergo propter hoc fallacy" which assumes causality from temporal sequence; a mere temporal relationship between an event and a patient's disease or symptoms does not allow an expert to place that event on a list of possible causes of the disease or symptoms. Case studies and clinical experience, used alone and not merely to bolster other evidence, are also insufficient to show general causation.

Here, none of the medical textbooks and epidemiological studies submitted by the expert came close to providing useful evidence of a definitive causal link between traumatic head injuries and autistic disorders, and none provided even marginal support for plaintiff's theory of a relationship between abnormal cerebral spinal fluid pressure and problems with cerebellum pressure, leading to autism. For example, the text chapter listing the known etiological factors involved in ASD does not mention acquired trauma in the perinatal brain.

Plaintiff also attempted to sidestep the deficiencies in the medical literature by focusing on the expert's experience and training. Merely demonstrating that an expert has experience, however, does not automatically render every opinion and statement by that expert reliable. The witness must explain how that experience leads to the conclusion reached, why that experience is a sufficient basis for the opinion, and how that experience is reliably applied to the facts. The trial court's gatekeeping function requires more than simply “taking the expert's word for it.”

Judgment for defendant affirmed.